Gastrointestinal immunophenotype in adenocarcinomas of the uterine cervix and related glandular lesions: a possible link between lobular endocervical glandular hyperplasia/pyloric gland metaplasia and 'adenoma malignum'

Characteristics of the magnetic resonance imaging findings of cervical gastric-type adenocarcinoma

AIMS

This study identified the distinct magnetic resonance imaging findings of cervical gastric-type adenocarcinoma (GAS) that can help differentiate it from squamous cell carcinoma (SCC) and usual-type endocervical adenocarcinoma (UEA) and reveal the radiologic-pathologic correlation.

MATERIALS AND METHODS

All consecutive patients with cervical GAS treated at our hospital from November 2009 to August 2021 were included. The SCC and UEA cases were considered controls. Tumor location, tumor shape, presence and size of cysts, presence of uterine fluid, and apparent diffusion coefficient (ADC) were evaluated.

RESULTS

Overall, 18 GAS, 55 SCC, and 23 UEA cases were evaluated. The tumor was located in the entire cervix in 13/18 GAS cases, whereas it was predominantly located in the lower cervix in 38/55 SCC cases and 14/23 UEA cases. Most GAS cases exhibited a diffuse infiltration growth pattern (17/18), whereas most SCC and UEA cases exhibited a mass-forming pattern (39/55 and 20/23, respectively). Moreover, the percentages of cases presenting microcysts or macrocysts and undergoing uterine fluid collection were significantly higher in the GAS group (14/18 and 13/18) than in the SCC and UEA groups. ADC was significantly higher in the GAS group than in the SCC group (1.092 × 10-3 vs. 0.819 × 10-3 mm2/s).

CONCLUSION

This study revealed that GAS is characterized by tumor presence in the entire cervix, infiltrative growth pattern, intrauterine fluid collection, and frequent microcyst or macrocyst formation. Moreover, ADC was significantly higher in the GAS group than in the SCC group.

Preoperative diagnosis of cervical cystic lesions using magnetic resonance imaging: a retrospective study

BACKGROUND

We conducted this study to clarify the magnetic resonance imaging (MRI) characteristics of lobular endocervical glandular hyperplasia (LEGH) and Nabothian cysts.

METHODS

This study included 48 patients who underwent hysterectomy at our institution between 2016 and 2020 for suspected LEGH. Histopathological studies confirmed the presence of 25 Nabothian cysts and 23 cases of LEGH. We retrospectively analyzed five characteristic MRI findings: (1) located at the upper cervical canal, (2) positioned within the cervical stroma, (3) not circumscribing the cervical canal, (4) low- to iso-intensity on T1-weighted images (T1WI), and (5) "cosmos" or "microcystic" pattern. We compared the diagnostic accuracy of these findings for LEGH and Nabothian cysts using sensitivity, specificity, and predictive values. Combinations of findings were also calculated.

RESULTS

The characteristics "cosmos" or "microcystic" pattern, lesion not circumscribing the cervical canal, and low/iso-intensity on T1WI had a sensitivity and specificity greater than 50%. The sensitivity was 73.9% and specificity 84.0% when a combination of "cosmos" or "microcystic" pattern and lesion not circumscribing the cervical canal was present.

CONCLUSION

The coexistence of a "cosmos" or "microcystic" pattern and not circumscribing the cervical canal was the most characteristic finding that distinguished LEGH from Nabothian cysts. When neither of these findings is present, Nabothian cyst can be suspected.

Gastric-type glandular lesions of the female genital tract excluding the cervix: emerging pathological entities

In the last two decades or so, a spectrum of benign, premalignant and malignant cervical glandular lesions exhibiting gastric differentiation has been described, with gastric-type adenocarcinoma representing the most common human papillomavirus (HPV)-independent cervical adenocarcinoma. More recently, limited literature has reported a variety of gastric-type glandular lesions at other sites within the female genital tract and, as in the cervix (the most common site for these lesions), a spectrum of benign, premalignant and malignant lesions has been proposed. We provide an update and review of the emerging spectrum of gastric-type glandular lesions at female genital tract sites other than the cervix. In the endometrium, putative gastric-type glandular lesions include mucinous metaplasia of gastric-type, atypical mucinous proliferation of gastric-type and gastric-type adenocarcinoma. Similarly in the vagina, gastric-type adenosis, atypical adenosis and adenocarcinoma have been described. There have also been occasional reports of gastric-type lesions involving the ovary and fallopian tube. We provide guidance on how to recognise gastric-type lesions morphologically and immunophenotypically and stress that sometimes these lesions occur at more than one site within the female genital tract (synchronous/multifocal gastric-type lesions of the female genital tract), sometimes in association with Peutz-Jeghers syndrome.

Comprehensive Molecular Profiling and Clinicopathological Characteristics of Gastric-Type Mucinous Carcinoma of the Uterine Cervix in Japanese Women

Gastric-type mucinous carcinoma (GAS) of the uterine cervix is the most common adenocarcinoma that develops independently of human papillomavirus infection; it is typically diagnosed at an advanced stage and has a poorer prognosis than usual-type endocervical adenocarcinoma. Few studies have examined the molecular profile of GAS, but genetic alterations in TP53 and STK11 have been repeatedly reported. We analyzed the clinicopathological characteristics and molecular profile of GAS. Fresh-frozen tissue specimens and formalin-fixed paraffin-embedded (FFPE) tissues from 13 patients with GAS treated between January 2000 and December 2020 were analyzed. We performed next-generation sequencing on eight fresh-frozen GAS specimens using the Cancer Hotspot Panel v2 (cases 1-8) and the FoundationOne companion diagnostic (F1CDx) assay on six FFPE samples (cases 8-13). Seventy-four genomic alterations were identified in 42 genes. In order of frequency, TP53, ATRX, CDKN2A, KRAS, APC, and STK11 were altered in at least three cases. Targetable genomic alterations were identified in all six patients' specimens analyzed using the F1CDx assay. GAS harbors various genomic alterations associated with sustained activation of signaling pathways or cell cycle regulation in addition to abnormalities in TP53, and precision medicine based on molecular profiling will be necessary to overcome GAS.

Gastric-type adenocarcinoma of the uterine cervix: clinical features and future directions

The concept of gastric-type mucinous carcinoma of the uterine cervix (GAS) has been accepted worldwide because of its aggressive clinical behaviour and the absence of high-risk human papilloma virus infection. The World Health Organization (WHO) 2020 classification divides cervical tumours into two categories: human papilloma virus-associated and human papilloma virus-independent. Hence, GAS is now classified as an human papilloma virus-independent gastric type. Because clinical studies have reported that GAS is refractory to conventional treatments such as chemotherapy and radiotherapy, especially at an advanced stage, and has aggressive features with widespread dissemination to unusual sites, such as the omentum, peritoneum and distant organs, it is urgent to establish new treatment strategies by comparing the molecular profiles of human papilloma virus-associated adenocarcinomas. A series of genetic mutations characteristic to GAS encourage the development of future treatment strategies such as targeted therapy and immunotherapy.

Atypical lobular endocervical glandular hyperplasia: two case report and literature review

Atypical lobular endocervical glandular hyperplasia (ALEGH) is considered a precancerous lesion of gastric-type adenocarcinoma (GAS)/minimal deviation adenocarcinoma (MDA) characterized by an insidious onset, atypical symptoms, and often negative human papillomavirus (HPV) screening. Early screening for this disease is challenging, leading to a high rate of missed clinical diagnoses and the development of malignant tumors at the onset. Increased vaginal discharge and the presence of imaging cystic masses at the internal cervical ostium are often observed in patients with ALEGH. Therefore, we reviewed the clinical data of two cases of ALEGH that were identified and diagnosed in the early stages at our hospital. Through a comprehensive analysis of the medical history and diagnosis plan, combined with a review of relevant literature, to improve the early recognition and diagnosis of ALEGH, as well as strengthen the management of cervical precancerous lesions.

Therapeutic target biomarkers of patient-derived xenograft models of gastric-type cervical adenocarcinoma

Background

Most cervical adenocarcinomas are associated with human papillomavirus (HPV). Gastric-type cervical adenocarcinoma (GAS), an HPV-independent adenocarcinoma, shows an aggressive clinical feature, resulting in a poor prognosis. Resistance to chemotherapy poses a difficulty in managing patients with metastatic GAS. We aimed to establish patient-derived xenografts (PDXs) of tumors from two patients with GAS and evaluated protein biomarkers for drug development using immunohistochemistry.

Methods

Two PDXs were established 78 and 48 days after transplanting the patient's tumor tissues into immunodeficient mice, respectively. PDX and patient's tumor samples were stained for HER2, HER3, PMS2, MSH6, PanTrk, and ARID1A to evaluate biomarkers for therapeutic targets. In addition, whole exome sequencing and RNA sequencing were performed on available samples.

Results

The pathological findings in morphological features and immunohistochemical profiles from the established PDXs were similar to those from the patients' surgical tumor specimens. HER3 was overexpressed in the patient's tumors, and the corresponding PDX tumors and HER2 was weakly stained in both types of tumor samples. In all PDX and patient tumor samples, PMS2, MSH6, and ARID1A were retained, and PanTrk was not expressed. In addition, a total of 10 samples, including tumor tissue samples from 8 other GAS patients, were evaluated for HER3 expression scores, all of which were 2 + or higher.

Conclusions

In summary, we evaluated biomarkers for therapeutic targets using newly established PDX models of GAS. Frequent HER3 overexpression and HER2 expression in GAS tumors suggest the possibility of new treatments for patients with GAS by targeting HER3 and HER2.

Synchronous mucinous metaplasia and neoplasia of the female genital tract with both pulmonary metastases and STK11/KRAS gene mutations: a case report

Multiple morphological changes in two or more sites of concurrent multifocal mucinous lesions in the female genital tract are indicative of SMMN-FGT, which is unrelated to high-risk HPV infection. MUC6 and HIK-1083 showed positive characteristic immunohistochemistry. Seldom is the condition described. Here we describe an SMMN-FGT patient who also had lung metastases and STK11/KRAS gene mutations. Based on the current researches, we hypothesize that SMMN-FGT is closely associated with the development of cervical gastric adenocarcinoma.

Intestinal‑type mucinous carcinoma of the endometrium showing a polypoidal exophytic form: A case report

Although endometrial cancer is a common malignancy in women, rare histological subtypes can pose diagnostic challenges. Primary endometrial intestinal-type mucinous carcinoma is a newly recognized subtype of endometrial cancer that differs from Müllerian-type endometrial mucinous carcinoma. The present case report documents a rare case of intestinal-type mucinous carcinoma of the endometrium showing a polypoidal exophytic form. The patient, an 80-year-old female, was incidentally diagnosed with a uterine tumor during a follow-up for vulvar Paget's disease. Clinical and imaging examinations revealed a localized mass within the uterine cavity. Hysteroscopy and subsequent histological examination confirmed the presence of intestinal-type mucinous carcinoma of the endometrium. Microscopically, the tumor displayed adenocarcinoma containing an intestinal-type glandular epithelium with mild nuclear atypia. It stained positive for the gastrointestinal markers mucin 2 and caudal type homeobox 2, and stained negatively for estrogen receptor α. The patient underwent surgery and adjuvant chemotherapy, with no evidence of recurrence at the latest follow-up 6 months after surgery. Endometrial intestinal-type mucinous carcinoma is a rare histological subtype of endometrial cancer. Differential diagnoses include Müllerian-type endometrial mucinous carcinoma, endocervical adenocarcinoma, metastasis from gastrointestinal tract adenocarcinoma and non-neoplastic gastric/intestinal metaplasia. However, the prognosis of endometrial intestinal-type mucinous carcinoma remains unclear due to limited reported cases. Existing evidence suggests a poorer prognosis compared with classical mucinous carcinomas of the endometrium. The present case, which is characterized by a polypoidal exophytic tumor without myometrial invasion, showed a favorable outcome. Further documentation and characterization of the aforementioned rare malignancy are necessary to enhance the understanding of its clinical physiology and outcomes. The present case report highlights the diagnostic challenges associated with intestinal-type mucinous endometrial carcinoma. The inclusion of this type of malignancy in the latest World Health Organization classification emphasizes the need for further comprehensive studies and case reports to expand the current knowledge on this rare histological subtype.

Discriminant Analysis Using Gabor Filter Sets for Lobular Endocervical Glandular Hyperplasia: Numerical Interpretation of Nuclear Atypia by Gabor Filter Features

INTRODUCTION

Lobular endocervical glandular hyperplasia (LEGH) is a benign lesion; however, it is considered to be the origin of gastric-type adenocarcinoma in the uterine cervix, and early diagnosis is important. At Shinshu University Hospital, screening of LEGH cells is based on the difference in color tone of cytoplasmic mucin on Papanicolaou staining and detection of gastric mucin using HIK1083-labeled latex agglutination assay. However, it is sometimes difficult to distinguish LEGH cells with subtle nuclear atypia from endocervical (EC) cells.

METHODS

We calculated the Gabor filter features (mean signal value, standard deviation, skewness, kurtosis) from the nuclei of cytological specimens in EC cells (37 cases) and LEGH cells (33 cases) using microscopic images, and we performed statistical analysis and discriminant analysis by linear support vector machine (LSVM) using these features. A Gabor filter is a linear filter defined as a mathematical representation of the mammalian visual system. Gabor filters with three wavelengths and eight angles were used for analysis.

RESULTS

Gabor filter features in EC cells were higher than in LEGH cells, demonstrating that the gradient of LEGH cell nuclei was milder than that of EC cell nuclei. The accuracy calculated using all Gabor filters was 91.0% and the accuracy of four Gabor filters (λ = 2/3π and θ = 0°, 45°, 90°, 135°) was 88.9%. High accuracy with low computation costs was achieved by reducing the number of features used for LSVM.

CONCLUSION

The application of a Gabor filter with convolutional processing resulted in the edges of LEGH cells being slightly rough and thick, whereas those of EC cells were fine and thin. Thus, it is thought that the frequency of abrupt gradients of pixels was higher in EC cells than in LEGH cells, and the gradient of chromatin distribution in LEGH cell nuclei was milder than that in EC cell nuclei. It was possible to evaluate nuclear findings of EC and LEGH cells objectively by quantifying morphological features of nuclei using Gabor filters. It was possible to differentiate EC cells from LEGH cells using LSVM using Gabor filter features.

Diagnostic Utility of Hysteroscopic Biopsy in Cases of Suspected Lobular Endocervical Glandular Hyperplasia and Comparison with Cervical Conization

BACKGROUND

Cervical cystic lesions encompass a range of benign and malignant pathologies. Magnetic resonance imaging or cytology alone cannot provide a definitive diagnosis, and conventional practice involves performing a cervical biopsy by conization to confirm the histology in cases exhibiting potential signs of lobular endocervical glandular hyperplasia (LEGH) or malignancy. However, as postoperative complications resulting from conization can impact future fertility and pregnancy, alternative diagnostic methods are needed for reproductive-age patients. This study aimed to establish the efficacy of a hysteroscopic biopsy for diagnosing cervical cystic lesions and compare it with conization.

METHODS

Thirteen patients with cervical cystic lesions suspected of LEGH or malignancy underwent a hysteroscopic biopsy, while 23 underwent conization. Patient background information, preoperative evaluation, histology, and postoperative outcomes were collected and compared retrospectively.

RESULTS

No significant differences were found between the hysteroscopy and conization groups in terms of mean patient age (45 vs. 48 years), operating time (23 vs. 35 min), blood loss (small amount vs. 43 mL), and postoperative hospitalization (1.1 vs. 1.6 days).

CONCLUSION

A hysteroscopic biopsy allows for targeted resection of the cervix while maintaining diagnostic accuracy. It may serve as an efficient method for diagnosing cervical cystic lesions.

Novel Strategy for the Management of Cervical Multicystic Diseases

PURPOSE

To investigate the clinical practices of diagnosing multicystic cervical lesions as a means to develop a more appropriate diagnostic algorithm for gastric-type adenocarcinoma (GAS) and its precursors.

METHODS

Clinical information for 159 surgically treated patients for multicystic disease of the uterine cervix was collected from 15 hospitals. We performed a central review of the MRI and pathological findings. The MRI findings were categorized into four types including two newly proposed imaging features based on the morphology and distribution of cysts, and the diagnosis accuracy was assessed. Among the four MRI types, types 1 and 2 were categorized as benign lesions that included LEGH; type 3 were precancerous lesions (with an assumption of atypical LEGH); and type 4 were malignant lesions.

RESULTS

The central pathological review identified 56 cases of LEGH, seven with GAS, four with another form of carcinoma, and 92 with benign disease. In clinical practice, over-diagnosis of malignancy (suspicion of MDA) occurred for 12/19 cases (63.2%) and under-diagnosis of malignancy occurred for 4/11 (36%). Among the 118 patients who had a preoperative MRI and underwent a hysterectomy, type 3 or 4 MRI findings in conjunction with abnormal cytology were positively indicative of premalignancy or malignancy, with a sensitivity and specificity of 61.1% and 96.7%, respectively.

CONCLUSIONS

Although the correct preoperative diagnosis of cervical cancer with a multicystic lesion is challenging, the combination of cytology and MRI findings creates a more appropriate diagnostic algorithm that significantly improves the diagnostic accuracy for differentiating benign disease from premalignancy and malignancy.

Current status and molecular biology of human papillomavirus-independent gastric-type adenocarcinoma of the cervix

This article reviews the findings of clinical studies on gastric-type adenocarcinoma of the cervix to date, outline the molecular biological features identified in recent studies, and discusses the future therapeutic strategies. Gastric-type adenocarcinoma of the cervix is a new classification in the World Health Organization 2014 classification. The World Health Organization 2020 classification further divides cervical tumors into two categories: human papillomavirus-associated and human papillomavirus-independent. Thus, gastric-type adenocarcinoma of the cervix is now classified as a human papillomavirus-independent gastric type. Clinical studies have reported that gastric adenocarcinoma of the cervix is refractory to conventional chemotherapy and radiotherapy, and it is desirable to elucidate its molecular biological mechanism. A series of gene mutations characteristic to the gastric-type adenocarcinoma of the cervix encourage the development of future treatment strategies.

Primary endometrial gastric (gastro-intestinal)-type carcinoma: A practical approach

The latest WHO classification of the female genital tract tumors introduces a new type of carcinoma: the primary gastric-type (or gastro-intestinal type) carcinoma of the endometrium. This type of neoplasm tends to have a poor outcome, making its correct diagnostic important. As little is known about this entity and given its quite challenging diagnosis, we aim to review existing data about it and propose a practical diagnostic approach. There are currently 11 cases published in 8 articles fitting the precise definition of a primary gastric-type carcinoma of the endometrium. Three main differential diagnoses must be excluded before considering this tumor: endometrioid adenocarcinoma with mucinous (Müllerian-type) differentiation, endocervical primary, and gastro-intestinal primary. Morphological aspects of this tumor can be heterogeneous and confusing; in this context, immunochemistry can be helpful to highlight the gastric or intestinal differentiation, but also to eliminate a mucinous endometrioid adenocarcinoma of Müllerian-type, by the constant negativity of estrogen receptors. A metastasis of a primary gastro-intestinal tract carcinoma must also be excluded by clinical, endoscopic and imaging work-up. Finally, an endometrial extension of a primary endocervical gastric-type carcinoma should be ruled out by complete sampling of the cervix. Intestinal type endocervical adenocarcinoma is easier to eliminate since this is an HPV-associated neoplasm.

Biology and management of lobular endocervical glandular hyperplasia

AIM

Lobular endocervical glandular hyperplasia (LEGH) is a multicystic proliferative disorder of the uterine cervix. The aim of this review was to clarify the current understanding of this unique tumor.

METHOD

This article reviews the chronological progress of research regarding clinico-pathological and genetic aspects of LEGH and related cervical cystic diseases such as Nabothian cyst and adenocarcinoma of gastric type (GAS), using the literature and data from our institute. We also describe clinical management including preoperative diagnosis and adequate surgical/expectant treatment based on the biological features.

RESULTS

Recent studies revealed several unique aspects of LEGH, that is, (i) production of gastric mucin, (ii) symptomatic and histological similarity with minimal deviation adenocarcinoma (MDA), and (iii) frequent association with GAS, including MDA. These findings indicated that LEGH is a gastric metaplasia, as well as pre-cancerous neoplasia. For the preoperative diagnosis of LEGH, the combination of "cosmos" sign on magnetic resonance imaging, detection of gastric mucin, and lack of nuclear atypia on cytology is important. Cone biopsy is effective for pathological diagnosis. Simple hysterectomy is indicated as surgical treatment for LEGH; however, meticulous follow-up is also an option, especially for young patients, because the rate of malignant transformation was reported to be 1%-2%. For LEGH patients who selected follow-up, a worsening cytology and increase in lesion size were important signs of malignant change of LEGH for safe follow-up.

CONCLUSION

Proper understanding of the characteristics of LEGH is important for adequate management.

Gastric-type Mucinous Carcinoma with an Abnormal Increase of CA199: A Case Report and Literature Review

Objective

Gastric-type mucinous carcinoma (GAS), as a rare subtype of mucinous adenocarcinoma, accounts for approximately 1%–3% of cervical adenocarcinoma. It was considered as a new type of cervical mucinous adenocarcinoma by the World Health Organization (WHO) in 2014. GAS represents more aggressive disease than does usual type endocervical adenocarcinoma (UEA).

Case report

A case of cervical adenocarcinoma with an abnormal increase of CA199 in a 50-year-old Chinese woman was reported. Our patient presented with abnormal vaginal discharge and combined with elevated Ca199 at the value of 2,729 U/mL. Imaging examinations showed no abnormalities. Diagnostic conical resection suggested cervical adenocarcinoma in situ. Post-operative pathology confirmed mucinous cervical adenocarcinoma (considering gastric type), infiltrating cervical interstitial >2/3, involving the deep myometrium, accompanied by vascular carcinoma infiltration and lymph node metastasis.

The patients received an extensive hysterectomy and post-operative adjuvant chemoradiotherapy. The chemotherapy regimen was paclitaxel, combined with platinum. After 20 months of follow-up, the patient showed no signs of recurrence.

Conclusion

Preoperative diagnosis of cervical adenocarcinoma is insidious and can be easily misdiagnosed. For patients with high preoperative Ca199, the possibility of GAS should be kept open.

Claudin-18 as a Promising Surrogate Marker for Endocervical Gastric-type Carcinoma

HIK1083 and trefoil factor 2 (TFF2) are known to be expressed in gastric-type carcinoma (GAS), but they do not reliably mark all GASs, and focal expression can be missed in biopsy specimens. We aimed to investigate whether claudin-18 and alpha-methylacyl-CoA racemase (AMACR) could be surrogate markers to separate GAS from other types of endocervical adenocarcinoma (ECA) and to compare their usefulness with that of HIK1083 and TFF2. Claudin-18 and AMACR immunohistochemistry was performed, and the results were compared with that of TFF2 and HIK1083, using whole sections of 75 ECAs (22 GASs and 53 non-GASs) and 179 ECAs with tissue microarrays (TMAs). TMAs were built to simulate the assessment of immunohistochemical stains in small biopsies. Any membranous (claudin-18) or cytoplasmic/membranous (AMACR, TFF2, HIK1083) staining of >5% of tumor cells was considered positive. Of 75 ECAs with whole sections, claudin-18 was significantly more frequently expressed in GASs (21/22) compared with non-GASs (8/53) (P<0.01). In ECAs with TMAs, claudin-18 expression was significantly frequent in GASs (15/23, 65.2%) than in non-GASs (3/152, 2.0%; all usual-type) (P<0.01). All claudin-18-positive GASs showed intense staining except 1 case. Claudin-18 shared the same degree of sensitivity and specificity with HIK1083 and TFF2. Three clear cell carcinomas were positive for claudin-18, but none showed intense staining. AMACR was expressed in a subset of ECAs and showed no impact in distinguishing between GAS and other ECAs. Our results suggest that claudin-18 is a promising surrogate marker to separate GAS from other types of ECA, including clear cell carcinoma.

Independent validation of distinct clinicopathological features and prognosis among usual-type, mucinous-type and gastric-type endocervical adenocarcinoma categorised by new WHO classification (2020)

The new World Health Organization (WHO) classification of tumours of the female genital tract (2020) divides endocervical adenocarcinoma (EAC) into human papilloma virus (HPV)-related adenocarcinoma (HPVA) and HPV-independent adenocarcinoma (HPVI) to underscore the morphological and pathogenetic correlation. It may be potentially prognostic. In this study, we appraised the new WHO classification in an independent, single institution-based EAC cohort from China to assess the clinicopathological features and prognostic value among tumour types. Our study cohort contained 402 consecutive, surgically excised EACs consisting of 298 (74.1%) HPVA, 88 (21.9%) HPVI and 16 (4%) adenocarcinomas not otherwise specified (NOS). Usual-type (55.7%) and gastric-type adenocarcinoma (GAC) (18.2%) was the most common type in HPVA and HPVI, respectively. Block p16 staining (94.7% vs 24.4%) and HPV mRNA signal (89.4% vs 0) were more common in HPVA than in HPVI (p<0.001). HPVI or GAC were more frequently associated with prognostically adverse variables including old age, large tumour size, deep invasion of the cervical wall, high tumour stage, spread of the upper genital tract, lymphovascular invasion, and mutant-type p53 expression, compared to HPVA or mucinous/usual-type HPVA, respectively (all p<0.001). In univariate survival analysis, HPVI had a worse overall survival and higher tumour recurrence compared to HPVA (p<0.05). Mucinous-type HPVA showed a worse prognosis than usual-type HPVA, but better than GAC (p<0.001). Multivariate survival analysis demonstrated that HPVI was independently associated with a worse overall survival and tumour recurrence (p<0.05) while GAC was an adverse prognostic factor independently of FIGO stage (p<0.05). Our findings validate the value of the new WHO classification in prognostic stratification and pathogenetic correlation in EAC and its subtypes.

Testing Algorithms for the Diagnosis of Malignant Glandular Tumors of the Uterine Cervix Histotyped per the International Endocervical Adenocarcinoma Criteria and Classification (IECC) System

The International Endocervical adenocarcinoma Criteria and Classification (IECC) categorizes tumors into human papilloma virus (HPV) associated (HPVA), not associated (NHPV), and invasive adenocarcinoma not otherwise specified (IA NOS). HPVA and NHPV encompass 11 histotypes and an algorithm of mucin content, HPV ribonucleic acid (RNA), estrogen receptor and GATA3 is proposed for the diagnosis of most. In this study, the IECC algorithm's diagnoses were compared with hematoxylin and eosin (H&E) based IECC histotyping. Kappa statistics measured performance agreement. With additional markers, hierarchical clustering by random forest (RF) classification identified the most discriminating between tumor types, and investigated other algorithms. Three pathologists independently reviewed digitized H&E images of n=152 primary cervical adenocarcinomas for IECC histotype and mucin content, and tissue microarrays for expression of HPV RNA by in situ hybridization and 16 antibodies by immunohistochemistry. Results were finalized by consensus. There were n=113 HPVA, n=22 NHPV, and n=17 IA NOS. Mucin was obvious in n=36 and limited in n=116. Among n=124 with satisfactory test results, HPV RNA was positive in n=96, estrogen receptor in n=72, and GATA3 in n=15. The IECC algorithm diagnosed n=99 which agreed with H&E histotyping in n=64 for a fair κ of 0.36 (95% confidence interval, 0.21-0.50): n=12 were undiagnosed and n=13 were IA NOS. Small sample sizes restricted RF to HPVA versus NHPV which were discriminated by p16, HPV RNA, and MUC6 with an area under the curve of 0.74 (95% confidence interval, 0.58-0.90). The IECC algorithm for histotyping under-performed. The RF algorithmin for categorization was favorable, but validation in larger studies and investigation of additional algorithms to discriminate between all IECC histotypes are needed.

Molecular Pathology of Human Papilloma Virus-Negative Cervical Cancers

Cervical cancer is the fourth most common cancer in women worldwide and is predominantly caused by infection with human papillomavirus (HPV). However, a small subset of cervical cancers tests negative for HPV, including true HPV-independent cancers and false-negative cases. True HPV-negative cancers appear to be more prevalent in certain pathological adenocarcinoma subtypes, such as gastric- and clear-cell-type adenocarcinomas. Moreover, HPV-negative cervical cancers have proven to be a biologically distinct tumor subset that follows a different pathogenetic pathway to HPV-associated cervical cancers. HPV-negative cervical cancers are often diagnosed at an advanced stage with a poor prognosis and are expected to persist in the post-HPV vaccination era; therefore, it is important to understand HPV-negative cancers. In this review, we provide a concise overview of the molecular pathology of HPV-negative cervical cancers, with a focus on their definitions, the potential causes of false-negative HPV tests, and the histology, genetic profiles, and pathogenesis of HPV-negative cancers.

Gynaecological or gastrointestinal origin? Recognising Müllerian neoplasms with gastrointestinal phenotype and determining the primary site in selected entities

Recognising metastatic gastrointestinal and pancreatobiliary tumours to gynaecological sites may be challenging, as primary Müllerian tumours can demonstrate similar histological features. Endocervical adenocarcinomas can be of gastric and intestinal types, endometrial lesions may show gastrointestinal phenotype, and finally, mucinous tumours with secondary involvement of the ovaries may mimic primary neoplasms. The aim of this review is to address selected neoplastic entities of the gynaecological tract with gastric and intestinal differentiation and provide helpful clinical and pathological parameters for the diagnosis. A brief overview of metastatic tumours originating from the gastrointestinal and pancreaticobiliary tracts is also provided, including the most common pathological features.

Clinicopathological features and outcomes in gastric-type of HPV-independent endocervical adenocarcinomas

BACKGROUND

We aimed to analyze the clinicopathological features and outcomes of patients with gastric-type of HPV-independent endocervical adenocarcinoma (GAS HPVI ECA), and compare them with non-GAS HPVI ECA cases.

METHODS

Thirty-eight GASs [including 17 minimal deviation adenocarcinoma (MDA), 21 non-MDA GAS] and 17 non-GAS HPVI ECAs were studied. Data of clinical features, pathological characteristics, treatment, and outcomes were evaluated.

RESULTS

The median age of patients with GAS and non-GAS HPVI ECA was 46 and 48 years, respectively (p = 0.93). Compared with non-GAS HPVI ECAs, GAS had more common complains of vaginal watery discharge (p = 0.04). GAS cases were also associated with higher clinical stage (p = 0.036), more common in deeper cervical stromal invasion (p = 0.002) and lymphoavascular invasion (p = 0.044). GAS was associated with worse median progression-free survival (PFS) (p = 0.02) and median overall survival (OS) (p = 0.03) over patients with non-GAS HPVI ECAs. MDA had similar clinical and pathological features and prognosis compared with non-MDA GAS. Of note, serum CA19-9 levels were significantly higher in GAS than that in non-GAS HPVI ECA cases.

CONCLUSIONS

GAS cases were more likely to have high risk pathological factors and poorer PFS and OS compared with non-GAS HPVI ECAs. Serum CA19-9 may be helpful for diagnosis and screening in patients with GAS.

Impact of Histopathological Risk Factors on the Treatment of Stage IB-IIB Uterine Cervical Cancer

In the past decade, the incidence of adenocarcinoma of the uterine cervix gradually increased. Recent literature revealed that the molecular pathogenesis differs by histological subtype, and the histological subtype should be considered in deciding treatments for patients with uterine cervical cancer. However, no treatment based on histological type or genomic signature has been recommended in various treatment guidelines. The Japanese treatment guidelines recommend either radical hysterectomy or definitive radiotherapy as primary treatment for patients with stage IB-IIB squamous cell carcinoma and a radical hysterectomy-based approach for those with non-squamous cell carcinoma because of its lower radiosensitivity. The impact of histological type on survival outcome of uterine cervical cancer is controversial. Our retrospective studies suggested that the difference in survival outcome by histological subtype might be remarkable with disease progression. Recent literature suggested that usual-type endocervical adenocarcinoma, which is the most common histological type of cervical adenocarcinoma, showed a similar survival outcome to squamous cell carcinoma. In contrast, gastric-type mucinous carcinoma of the uterine cervix, which has aggressive clinical behavior and is not associated with high-risk human papillomavirus infection, showed resistance to chemotherapy and radiotherapy. Importantly, gastric-type mucinous carcinoma is rather common in Japan, compared with Western countries. It is therefore conceivable that the survival outcome of non-squamous cell carcinoma may be affected by regional difference in the frequency of gastric-type mucinous carcinoma. A molecular target to refractory uterine cervical cancer, such as gastric-type mucinous carcinoma of uterine cervix, still remains to be identified.

Clinicopathological and prognostic significance of immunophenotypic characterization of endocervical adenocarcinoma using CLDN18, CDH17, and PAX8 in association with HPV status

In 2020, the WHO published a new system for classifying invasive endocervical adenocarcinoma based on histological features and high-risk human papillomavirus (HPV) infection. However, immunophenotypes of each histological subtype require further investigation. We immunohistochemically analyzed 66 invasive endocervical adenocarcinomas using three cell-lineage-specific markers: claudin 18 (CLDN18) for gastric, cadherin 17 (CDH17) for intestinal, and PAX8 for Müllerian epithelial cells. We identified five immunophenotypes of endocervical adenocarcinoma: gastric (21%); intestinal (14%); gastrointestinal (11%); Müllerian (35%); and not otherwise specified (NOS) (20%). Adenocarcinomas with gastric immunophenotype, characterized by aging (p = 0.0050), infrequent HPV infection (p < 0.0001), concurrent lobular endocervical glandular hyperplasia (p = 0.0060), lymphovascular invasion (p = 0.0073), advanced clinical stage (p = 0.0001), and the poorest progression-free (p < 0.0001) and overall (p = 0.0023) survivals, were morphologically compatible with gastric-type adenocarcinoma of the WHO 2020 classification. Conversely, most adenocarcinomas with Müllerian (91%) and intestinal (89%) immunophenotypes were HPV associated and morphologically compatible with usual- or intestinal-type adenocarcinomas of the WHO 2020 classification. The morphology of adenocarcinomas with gastrointestinal immunophenotype was intermediate or mixed between those of gastric and intestinal immunophenotypes; 57% were HPV associated. Adenocarcinomas with NOS immunophenotype were mainly HPV associated (85%) and histologically poorly differentiated. Multivariate analysis revealed that gastric (p = 0.008), intestinal + gastrointestinal (p = 0.0103), and NOS (p = 0.009) immunophenotypes were independent predictors of progression-free survival. Immunophenotypes characterized by CLDN18, CDH17, and PAX8 exhibited clinicopathological relevance and may improve the diagnostic accuracy and prognostic value of conventional histological classification.

Peuzt - Jeghers syndrome with gastric type mucinous endocervical adenocarcinoma in a young woman: A case report

Introduction

Patients with Peutz-Jeghers syndrome (PJS) have high risk of malignancies, including gynecological cancers. Gastric type mucinous cervical adenocarcinoma might be presented in about 11–17% of PJS patients but the literature about this is limited.

Case presentation

We presented a rare case of a 39-year-old Vietnamese woman with Peutz-Jeghers syndrome who has gastric type adenocarcinoma (GAS) of the cervix. She underwent radical hysterectomy, and the diagnosis was confirmed on final pathology.

Conclusions

Oncologists and pathologists should recognize this rare clinical scenario for early diagnosis and treatment. This subtype also has an aggressive nature and poor prognosis.

•

Gastric type adenocarcinoma of the uterine cervix (GAS) is a rare variant of endocervical adenocarcinoma.

•

An association exists between GAS and Peutz-Jeghers syndrome.

•

Careful evaluation by gynecological oncologists is needed for early detection and treatment of this condition.

Decreased Gastric Gland Mucin-specific O-glycans Are Involved in the Progression of Ovarian Primary Mucinous Tumours

Ovarian primary mucinous tumours (OPMTs) show an adenoma–borderline–carcinoma sequence with gastrointestinal metaplasia. Gastric gland mucin-specific O-glycans are unique with an α1,4-linked N-acetylglucosamine (αGlcNAc) residue attached to mucin 6 (MUC6). Although αGlcNAc is expected to be expressed in OPMTs, the relationship between αGlcNAc expression and OPMT progression remains unknown. Here, we analysed 104 areas of benign mucinous tumours (benign), 55 areas of borderline mucinous tumours (borderline), and 18 areas of malignant mucinous tumours (malignant) to investigate the expression patterns of αGlcNAc, mucin 2 (MUC2), mucin 5AC (MUC5AC), and MUC6 during the progression of OPMT from benign to malignant. MUC5AC expression was observed in all areas. The frequencies of MUC6- and αGlcNAc-positive areas were decreased with tumour progression. In particular, the decrease in αGlcNAc-positive areas was remarkable. Furthermore, αGlcNAc expression was lower than MUC6 expression at all grades (benign, p < 0.0001; borderline, p = 0.0014; malignant, p = 0.0039). Conversely, there was no difference in the expression frequency or level of MUC2 among the three grades. These results suggest that decreased expression of αGlcNAc relative to MUC6 occurs early in tumour development and marks the initiation of OPMT progression.

A retrospective study on incidence, diagnosis, and clinical outcome of gastric-type endocervical adenocarcinoma in a single institution

Background

Gastric-type endocervical adenocarcinoma is rare but the most common subtype of cervical adenocarcinoma not associated with human papillomavirus. It is more aggressive with a shorter five-year survival rate compared to human papillomavirus-associated usual type endocervical adenocarcinoma. The objectives of our study were to determine the incidence and clinical-pathological characteristics of Gastric-type endocervical adenocarcinoma in a single institution.

Methods

Twenty four cases of invasive cervical adenocarcinoma were identified between January 2000 and December 2015, from the Saskatoon Health Region pathology database using International Endocervical Adenocarcinoma Criteria and Classification to retrospectively classify endocervical adenocarcinoma. Immunohistochemistry was performed with antibodies for Gastric mucin-6 (MUC-6), p16^INK4a, cyclin-dependent kinase inhibitor 2A (p16), p53 protein (p53), estrogen and progesterone receptors. Clinical and pathological data was retrieved from pathology reports and charts. Statistical analysis was performed using Mann-Whitney U test and Chi-Square test.

Results

Using the International Endocervical Adenocarcinoma Criteria and Classification criteria, 19 cases (79.2%) were classified as human papillomavirus-associated usual type endocervical adenocarcinoma, and five cases (20.8%) as Gastric-type endocervical adenocarcinoma. In our study 40% of Gastric-type endocervical adenocarcinoma cases presented at stage III compared to none of the usual type endocervical carcinoma cases. All the Gastric-type endocervical adenocarcinoma cases were positive for MUC-6, and negative for p16. 60% Gastric-type endocervical adenocarcinoma cases demonstrated mutant type p53 staining. In contrast, 84.2% of human papillomavirus-associated usual type endocervical adenocarcinoma cases showed block like nuclear and cytoplasmic positivity with p16 antibodies. The Gastric-type endocervical adenocarcinoma group had significantly shorter median survival time than human papillomavirus-associated usual type endocervical adenocarcinoma group, Gastric-type endocervical adenocarcinoma is 22 months compared to human papillomavirus-associated usual type endocervical adenocarcinoma at 118 months (p = 0.043).

Conclusions

In this study, Gastric-type endocervical adenocarcinoma accounted for 20.8% of all cervical adenocarcinoma with higher stage at presentation and shorter overall survival. Criteria proposed by International Endocervical Adenocarcinoma Criteria and Classification (IECC) are simple and reproducible in differentiating between, HPV- associated (HPVA) and non HPV associated (NHPVA) endocervical adenocarcinoma. Although none of the IHC assays is specific for GAS, but p16, MUC-6, ER, PR and p53 may further aid in confirming GAS and to differentiate it from benign and malignant mimics.

Minimal deviation adenocarcinoma with elevated CA19-9: A case report

BACKGROUND

Minimal deviation adenocarcinoma is a rare malignancy with a high rate of misdiagnosis and high aggressiveness, and its diagnosis relies on histopathology. Surgical resection is the preferred and most effective treatment, but the outcomes are often unsatisfactory.

CASE SUMMARY

A 60-year-old perimenopausal woman was admitted to the hospital and found to have elevated CA19-9 on physical examination without abdominal pain or vaginal bleeding. Clinical examination and positron emission tomography/computed tomography examination were unremarkable, magnetic resonance imaging examination was suggestive of dominant cervical lesions, and methylation examination was suggestive of malignant lesions. Tissue samples were taken from the suspected cervical lesion, and the final pathologic diagnosis was minimal deviation adenocarcinoma. Based on the pathologic diagnosis of suspected minimal deviation adenocarcinoma, radical abdominal total hysterectomy, bilateral oophorectomy, and pelvic and para-aortic lymph node dissection were performed. The final histological report confirmed minimal deviation adenocarcinoma of the cervix, stage IB2, with lymph node metastasis. Minimal deviation adenocarcinoma is a tumor with aggressive clinical behavior.

CONCLUSION

Patients with minimal deviation adenocarcinoma have a lower survival rate than patients with conventional human papillomavirus-related cervical adenocarcinoma. A precise preoperative pathologic diagnosis may reduce the mortality rate due to missed optimal treatment with multiple surgical interventions. To date, there is no therapeutic consensus; therefore, each case must be treated individually.

Clinico-pathological characteristics of patients with stage IB1-IB2 (FIGO 2018) uterine cervical cancer: a nationwide study in Japan

OBJECTIVE

The aim of this retrospective analysis is to reveal clinicopathological findings and clinical outcome of patients with stage IB1/IB2 (FIGO 2018) uterine cervical cancer.

METHODS

Based on the database of the Japanese Gynecologic Oncology Group, 2194 patients with stage IB1/IB2 (FIGO 2018), who underwent radical hysterectomy between 1/1/2004-12/31/2008, were identified as eligible for this retrospective study.

RESULTS

Patients with squamous cell carcinoma had significantly frequent lympho-vascular space invasion than those with non-squamous cell carcinoma in both stage IB1 and IB2 (stage IB1; 29.1% vs. 17.1%, p < 0.0001, stage IB2; 50.5% vs. 39.7%, p = 0.0009). Among 1262 patients with stage IB1, 61.2% (772/1262) were low-risk group, 29.4% (371/1262) were intermediate-risk group (single risk: 23.3%, double risks: 6.1%). Of 932 patients with stage IB2, 32.1% (299/932) were low-risk group, 59.1% (551/932) were intermediate-risk group (single intermediate-risk: 31.0%, double intermediate-risk: 28.1%). Disease-free survival rate and overall survival rate of stage IB1 patients were significantly better than those with stage IB2 (5-year DFS; 94.7% vs. 88.6%, p < 0.001, 5-yrs OS; 98.5% vs. 95.1%, p < 0.001). Stage IB1 Patients with double intermediate-risk showed significantly worse survival than those with single intermediate-risk (5-yrs DFS: 96.1% vs. 84.6%, p < 0.001, 5-yrs OS: 98.9% vs. 93.0%, p = 0.029). Multivariate analysis revealed that double intermediate-risk was the independent prognostic factor in stage IB1, but non-squamous cell carcinoma and intermediate-risk in stage IB2.

CONCLUSION

Non-squamous cell carcinoma and intermediate-risk decreased survival in patients with stage IB2, whereas double intermediate-risk was a negative impact on survival in stage IB1.

Massively parallel sequencing analysis of 68 gastric-type cervical adenocarcinomas reveals mutations in cell cycle-related genes and potentially targetable mutations

Gastric-type cervical adenocarcinoma (GCA) is an aggressive type of endocervical adenocarcinoma characterized by mucinous morphology, gastric-type mucin, lack of association with human papillomavirus (HPV) and resistance to chemo/radiotherapy. We characterized the landscape of genetic alterations in a large cohort of GCAs, and compared it with that of usual-type HPV-associated endocervical adenocarcinomas (UEAs), pancreatic adenocarcinomas (PAs) and intestinal-type gastric adenocarcinomas (IGAs). GCAs (n = 68) were subjected to massively parallel sequencing targeting 410-468 cancer-related genes. Somatic mutations and copy number alterations (CNAs) were determined using validated bioinformatics methods. Mutational data for UEAs (n = 21), PAs (n = 178), and IGAs (n = 148) from The Cancer Genome Atlas (TCGA) were obtained from cBioPortal. GCAs most frequently harbored somatic mutations in TP53 (41%), CDKN2A (18%), KRAS (18%), and STK11 (10%). Potentially targetable mutations were identified in ERBB3 (10%), ERBB2 (8%), and BRAF (4%). GCAs displayed low levels of CNAs with no recurrent amplifications or homozygous deletions. In contrast to UEAs, GCAs harbored more frequent mutations affecting cell cycle-related genes including TP53 (41% vs 5%, p < 0.01) and CDKN2A (18% vs 0%, p = 0.01), and fewer PIK3CA mutations (7% vs 33%, p = 0.01). TP53 mutations were less prevalent in GCAs compared to PAs (41% vs 56%, p < 0.05) and IGAs (41% vs 57%, p < 0.05). GCAs showed a higher frequency of STK11 mutations than PAs (10% vs 2%, p < 0.05) and IGAs (10% vs 1%, p < 0.05). GCAs harbored more frequent mutations in ERBB2 and ERBB3 (9% vs 1%, and 10% vs 0.5%, both p < 0.01) compared to PAs, and in CDKN2A (18% vs 1%, p < 0.05) and KRAS (18% vs 6%, p < 0.05) compared to IGAs. GCAs harbor recurrent somatic mutations in cell cycle-related genes and in potentially targetable genes, including ERBB2/3. Mutations in genes such as STK11 may be used as supportive evidence to help distinguish GCAs from other adenocarcinomas with similar morphology in metastatic sites.

An Emerging Anti-p16 Antibody-BC42 Clone as an Alternative to the Current E6H4 for Use in the Female Genital Tract Pathological Diagnosis: Our Experience and a Review on p16ink4a Functional Significance, Role in Daily-Practice Diagnosis, Prognostic Potential, and Technical Pitfalls

Background: To date, useful diagnostic applications of p16 IHC have been documented in gynecological pathology both for HPV-related and non-HPV-related lesions. In the present article, we reported our experience with the novel anti-p16 INK4a antibody (clone BC42), whose expression was tested across all different gynecologic neoplasms; we also compared it to the traditional E6H4 clone. Moreover, we discussed and explored all the diagnostic applications of p16 IHC in gynecologic pathology. Methods: Consultation cases covering a 5-year period (2016–2020) regarding gynecological neoplastic and non-neoplastic lesions in which immunohistochemistry for p16, clone E6H4 was originally performed, were retrospectively retrieved from the files of our institution. Immunohistochemical staining for p16ink4a (BC42) [Biocare Medical group-Paceco USA; Bioptica Milan] and p16ink4a (E6H4) [Ventana Medical Systems-Arizona USA; Roche] was performed by using the Ventana automated immunostainer (Ventana Medical Systems, Tucson, AZ, USA). The immunostaining pattern was defined as negative, focal/patchy, or diffuse. Results: A total of 196 cases, represented by 36 high-grade SIL/CIN3 of the uterine cervix, 30 cervical adenocarcinomas, 22 cervical squamous cell carcinoma, 70 endometrial carcinomas, 25 high grade serous ovarian carcinomas, 6 uterine adenomatoid tumors, and 10 uterine leiomyosarcomas were included in this study. Results showed concordant staining quality of both clones on all tested neoplastic tissues. Conclusions: The novel anti-p16 antibody (BC42 clone) appeared as an alternative to the current E6H4 for use in gynecological neoplasms, offering similar levels of positivity and equally reliable staining results.

Diffuse expression of MUC6 defines a distinct clinicopathological subset of pulmonary invasive mucinous adenocarcinoma

Invasive mucinous adenocarcinoma (IMA) of the lung is a unique variant of lung adenocarcinoma. Aberrant mucin expression is associated with cancer development and metastasis. However, the clinicopathological significance of mucin expression in IMA is not fully understood. Herein, we evaluated the clinicopathological, immunohistochemical, and molecular characteristics of 70 IMA tumors. EGFR, KRAS, GNAS, and TP53 mutations were assessed by PCR-based sequencing. Next-generation sequencing was used to assess cases without EGFR/KRAS mutations. A NanoString-based screening for fusions was performed in all IMAs without mitogenic driver mutations. Expression of mucins (MUC1, MUC2, MUC4, MUC5AC, and MUC6) was evaluated by immunohistochemistry and categorized as follows: negative (<10% of tumor cells), patchy expression (<90% of tumor cells), or diffuse expression (≥90% of tumor cells). Immunohistochemical testing for transcription factors (TTF-1, CDX2, HNF1β, HNF3α, HNF3β, and HNF4α) was also performed. As expected, KRAS mutations were the most common (in 67% of cases), followed by small numbers of other alterations. Patchy or diffuse expression of MUC1, MUC2, MUC4, MUC5AC, and MUC6 was observed in 52% or 6%, 3% or 0%, 30% or 3%, 26% or 73%, and 59% or 27% of cases, respectively. Furthermore, all IMAs were generally positive for HNF1β (100%), HNF3α (100%), HNF3β (100%), and HNF4α (99%) but were positive less often for TTF-1 (6%) and CDX2 (9%). Overall, there was no significant correlation between mucin expression and transcription factor expression. Unexpectedly, diffuse expression of MUC6 was significantly associated with KRAS-wild-type tumors (p = 0.0008), smaller tumor size (p = 0.0073), and tumors in female patients (p = 0.0359) in multivariate analyses. Furthermore, patients with tumors exhibiting diffuse MUC6 expression had significantly favorable outcomes. Notably, none of these patients died of the disease. Our data suggested that diffuse expression of MUC6 defines a distinct clinicopathological subset of IMA characterized by wild-type KRAS and possibly less aggressive clinical course.

Genetic characteristics of gastric-type mucinous carcinoma of the uterine cervix

Gastric-type mucinous carcinoma (GAS) is a recently established variant of endocervical mucinous adenocarcinoma that is characterized as being unrelated to HPV and having aggressive behavior and chemoresistance. GAS has a distinct morphology resembling nonneoplastic gastric glands or pancreaticobiliary adenocarcinoma, and their possible genetic similarity has been posed. In this study, next-generation sequencing was performed in 21 GAS cases using a customized panel including 94 cancer-associated genes. A total of 54 nonsynonymous somatic mutations were detected with an average mutation rate of 2.6 per lesion (range: 0-9). The most frequently mutated gene was TP53 (11/21, 52.4%), followed by STK11, HLA-B, PTPRS (4/21, 19.0%), FGFR4 (3/21, 14.3%), GNAS, BRCA2, ELF3, ERBB3, KMT2D, SLX4 (2/21, 9.5%), CDH1, EPCAM, KRAS, MLH1, RNF43, SNAI1, TWIST1, ZEB1, ZEB2, and so on (1/21, 4.8%). The mutated genes were mostly involved in signal transduction, DNA damage repair, and epithelial-mesenchymal transition (EMT). Correlation of TP53 mutation and p53 protein expression demonstrated that 31.3% with abnormal p53 expression harbored wild-type TP53. Compared to genetic features of gastric and pancreaticobiliary adenocarcinoma, TP53 mutations were frequent in both GAS and gastrointestinal adenocarcinoma. While KMT2D, ERBB3, and RNF43 mutations were shared between GAS and gastric adenocarcinoma, highly mutated genes in pancreatic ductal adenocarcinoma such as KRAS, SMAD4, and CDKN2A were rarely mutated in GAS. Of frequently mutated genes in cholangiocarcinoma, BAP1 and HLA-B were identified in GAS. Frequent EMT-related gene mutations suggested a possible role of EMT-related pathways in tumor dissemination and chemoresistance of GAS. In addition, GAS shared some genetic features with gastrointestinal adenocarcinoma. These findings provide a clue in understanding the biological basis of GAS.

The Role of Predictive Biomarkers in Endocervical Adenocarcinoma: Recommendations From the International Society of Gynecological Pathologists

To review the scientific evidence related to predictive biomarkers in cervical adenocarcinoma (ADC). The authors reviewed the literature regarding predictive biomarkers in cervical ADC. There were several limitations: (1) there is an overlap between predictive and prognostic biomarkers, as the vast majority of patients are treated with anticancer strategies; (2) in many studies and clinical trials, cervical ADC patients are included in a large series of patients predominantly composed of cervical squamous cell carcinomas; and (3) in most of the studies, and clinical trials, there is no distinction between human papillomavirus (HPV)-associated and HPV-independent cervical ADCs, or between various histologic subtypes. Results obtained from a small group of studies confirm that cervical ADCs exhibit distinct molecular features as compared with squamous carcinomas, and that there are different molecular features between different types of cervical ADCs. Promising areas of interest include ERBB2 (HER2) mutations and PD-L1 expression as predictive biomarkers for anti-HER2 treatment and immunotherapy, respectively. To date, no definitive data can be obtained from the literature regarding predictive biomarkers for cervical ADC. Clinical trials specifically designed for endocervical ADC patients are required to elucidate the predictive value of HER2 mutations and PD-L1 expression. The distinction between HPV-associated and HPV-independent cervical ADCs as well as early involvement of pathologists in the design of future clinical trials are needed to identify new predictive biomarkers in cervical ADC.

An unusual presentation of usual-type endocervical adenocarcinoma with lobular endocervical glandular hyperplasia: A case report

Uterine cervical hematoma is rare. A 51-year-old woman underwent pelvic magnetic resonance imaging (MRI) for uterine tumor survey. A large hematoma with cystic and solid lesions was observed in the uterine cervix. Follow-up MRI after 5 days revealed that the hematoma had decreased in volume. Pathological examination after surgery suggested there was usual-type endocervical adenocarcinoma (UEA) in the lower cervix and lobular endocervical glandular hyperplasia (LEGH) in the upper cervix, along with the cervical hematoma. The findings of this case suggest that the uterine cervical hematoma was secondary to either UEA or LEGH.

•

Uterine cervical hematoma is rare.

•

In the present case, the hematoma was considered to be caused by either the usual-type endocervical adenocarcinoma or lobular endocervical glandular hyperplasia.

•

The exact mechanism of the hematoma formation was unclear.

•

Usual-type endocervical adenocarcinoma and lobular endocervical glandular hyperplasia can be considered as differential diagnosis in cases of cervical hematoma.

Trefoil Factor 2 (TFF2) as a Surrogate Marker for Endocervical Gastric-type Carcinoma

Gastric-type carcinoma (GAS) is the most common human papilloma virus-independent endocervical adenocarcinoma (ECA), characterized by an aggressive behavior. Trefoil factor 2 (TFF2) is a mucin-associated peptide expressed in normal gastric but not endocervical glands. This study was carried out to investigate whether TFF2 could be a surrogate marker to separate GAS from other types of ECA. ECAs from 9 international institutions were reviewed for consensus histotype. Of them, expression of TFF2 was immunohistochemically examined compared with that of HIK1083, using whole sections of 50 ECAs (10 GASs and 40 non-GASs) and 179 ECAs (24 GASs and 155 non-GASs) with tissue microarrays (TMAs). TMAs were assessed to simulate assessment of immunohistochemical stains in small biopsies. Both markers were similarly scored, and any cytoplasmic/membranous staining of >5% of tumor cells was considered positive. Of 50 ECAs with whole sections, TFF2 was significantly more frequently expressed in GASs (8/10) compared with non-GASs (5/40) (P<0.01). In 179 ECAs with TMAs, TFF2 was also significantly more frequently expressed in GASs (7/24) compared with non-GASs (4/155) (P<0.01). There was no significant difference in specificity among the 2 markers. Double positivity for TFF2 and HIK1083 in ECAs was highly specific in separating GASs from non-GAS (P<0.01). A significantly smaller percentage of GASs were TFF2 positive in TMAs than in whole sections (P<0.01). Our results suggest that TFF2 is a promising marker, along with HIK1083, to confirm a diagnosis of GAS. This marker may be negative in small biopsies, indicating the necessity of using other exclusionary markers in combination with rigorous morphologic review and extensive sampling in resection specimens.

Adenocarcinoma of the Uterine Cervix: Immunohistochemical Biomarker Expression and Diagnostic Performance

Immunohistochemistry (IHC) improves the diagnosis of cervical adenocarcinoma but is not adequately studied. The performance of 16 antibodies previously reported as potentially discriminating between some histotypes was investigated in 184 tumors comprised of 12 histotype groups collapsed into 3 categories [47 adenocarcinomas in situ (AIS), 121 probable human papillomavirus-dependent adenocarcinomas (HPVD), and 16 of probable independence (HPVI)]. IHC sections from 5 tissue microarrays were scanned, and 3 pathologists independently reviewed images to assess staining percentages and intensities. Biomarker expression was based on published positive and negative cutoffs and agreement between any 2 pathologists. Differences between the 3 categories in the hierarchical ranking of biomarker positivity were analyzed by Random Forest classification, and between select groups by Unsupervised Hierarchical Clustering. Important category discriminants were combined in logistic regression models and the area under the curve (AUC) computed. Potential group discriminants were terminal cluster biomarkers with a 50% or more difference in positivity. Strong associations occurred between the lower expression of carcinoembryonic antigen and stromal actin in AIS compared with HPVD [AUC=0.70, 95% confidence interval (CI), 0.59-0.80] and in the higher expression of p16 and estrogen receptor in comparison to HPVI (AUC=0.86, 95% CI, 0.73-0.98), and between the higher expression of p16, carcinoembryonic antigen and estrogen receptor in HPVD compared with HPVI (AUC=0.88, 95% CI, 0.77-0.99). Between select groups, 9 biomarkers emerged as potential discriminants. Select IHC biomarkers can discriminate AIS from invasive adenocarcinomas, and invasive adenocarcinomas stratified by human papillomavirus dependency from each other. Independent replication in larger studies is needed, and to confirm discriminants of histotype groups.

Cytomorphologic Features of Gastric-Type Endocervical Adenocarcinoma in Liquid-Based Preparations

OBJECTIVE

Gastric-type endocervical adenocarcinoma (GAS) is a recently described, uncommon, and aggressive tumor with distinct morphologic features and HPV-independent etiology. Data on GAS in liquid-based cytology (LBC) Papanicolaou (Pap) test preparations from a North American patient population are scant. We systematically assessed the cytomorphologic characteristics of GAS in LBC from patients in Ontario and examined if glandular cell nuclear area could represent a readily assessable feature which may aid in GAS detection.

STUDY DESIGN

Pap test slides preceding the diagnosis of GAS were retrieved locally or requested from outside laboratories. A structured review of 15 cytomorphologic features was performed using the available LBC Pap test slides of GAS and a set of usual-type endocervical adenocarcinomas (UEA). Morphometry of the glandular cell nuclear area was performed, and normalized values were compared to UEA and benign endocervical cells.

RESULTS

At least 1 Pap test (5 ThinPrep®, 11 SurePath®, and 1 direct smear) was available for 14 patients. Original LBC Pap test diagnoses were negative for intraepithelial lesion or malignancy (NILM) (7), adenocarcinoma/carcinoma (6), atypical glandular cells (2), and adenocarcinoma in situ (1). Review detected abnormal glandular cells in 6/7 NILM cases. Honeycomb-like sheets, nuclear enlargement, and microvesicular cytoplasm were the single most common architectural, nuclear, and cytoplasmic features, respectively. Microvesicular cytoplasm (100 vs. 17%), honeycomb-like sheets (87 vs. 8%), prominent nucleoli (93 vs. 25%), and anisonucleosis (93 vs. 50%) were most discriminatory for GAS versus UEA, respectively. Yellow mucin, intranuclear cytoplasmic pseudoinclusions, and goblet/Paneth-like cells were uncommon, but unique for GAS. Glandular cell nuclear area normalized to neutrophils was found to be significantly increased in GAS compared to benign endocervical cells.

CONCLUSIONS

GAS is under-recognized and may mimic reactive endocervical cells. Awareness of the tumor type and its cytomorphology is critical for early detection. Identification of glandular cells with uniform nuclear enlargement in conjunction with any of the other cytologic features may help avoid false-negative Pap results. Neutrophils may serve as convenient size reference and visual aid.

Uncommon Cervical Lesions: A Review and Discussion of the Differential Diagnosis

CONTEXT.—

While the vast majority of cervical tumors consist of human papillomavirus (HPV)-related squamous cell carcinoma or adenocarcinoma, a subset of rare tumor types, frequently unrelated to HPV, does occur in this location. These tumors vary widely in prognostic and therapeutic implications, and accurate recognition is crucial to providing appropriate treatment. Some are benign or portend a favorable prognosis (adenoid basal carcinoma, ectopic prostate tissue), while others are frankly malignant lesions with a less favorable prognosis (adenoid cystic carcinoma, HPV-negative endocervical adenocarcinoma, mesonephric adenocarcinoma, clear cell carcinoma, small cell carcinoma, and adenosquamous carcinoma).

OBJECTIVE.—

To review the morphologic features of uncommon cervical lesions, the utility of immunohistochemistry for distinction between these entities, and the clinical and prognostic implications of accurate diagnosis.

DATA SOURCES.—

University of Michigan cases and review of the pertinent literature regarding the entities described.

CONCLUSIONS.—

Key morphologic and immunohistochemical features detailed herein will allow for the accurate distinction between these uncommon cervical lesions. Morphology is most useful in discriminating between the entities, as there is frequent immunohistochemical overlap between them; however, in rare instances immunohistochemistry can be useful in resolving the diagnosis.

Limited frequency of malignant change in lobular endocervical glandular hyperplasia

Introduction

Although lobular endocervical glandular hyperplasia is a benign disorder of the uterine cervix, its potential as a precursor of minimal deviation adenocarcinoma has been reported. However, the natural history of the disease and the frequency of malignant change are not fully understood. We evaluated the frequency of malignant change of clinical lobular endocervical glandular hyperplasia and explored useful parameters indicating malignant change.

Methods

The clinical courses of 175 patients with cervical multi-cystic lesions who visited Shinshu University Hospital between June 1995 and June 2019 were retrospectively analyzed. We examined the results of follow-up and outcomes of the patients diagnosed with lobular endocervical glandular hyperplasia and investigated the frequency of malignant transformation.

Results

Of the 175 patients, 15, 84, and 76 were clinically diagnosed with suspected malignancy, suspected lobular endocervical glandular hyperplasia, and suspected nabothian cyst, respectively. Of these patients, 69 patients with suspected lobular endocervical glandular hyperplasia were followed, and 12 underwent hysterectomy after a mean follow-up of 57.1 (range: 3–154) months due to lesion enlargement (increase in tumor diameter of >20%) and/or worsening cytology. Of these 12 patients, two had lobular endocervical glandular hyperplasia with atypia and one had minimal deviation adenocarcinoma. Of 69 patients, the rate of malignant change was 1.4% (1/69). The growth rates of the lesions for these three patients during follow-up were significantly higher than those of nine patients who underwent surgery with lobular endocervical glandular hyperplasia without atypia and 48 follow-up cases of suspected lobular endocervical glandular hyperplasia. The cut-off value of the growth rate suggesting malignant transformation was 38.1% (84.6% sensitivity and 100% specificity). Tumor size and cytology did not change in the remaining 57 cases continuing follow-up.

Conclusion

An increase in tumor size and worsening cytology are important parameters for detecting malignant transformation of lobular endocervical glandular hyperplasia during follow-up. However, the frequency of malignant change of this disease may be limited. These results suggest that conservative management may be an option for clinical lobular endocervical glandular hyperplasia.

The Evolving Spectrum of Precursor Lesions of Cervical Adenocarcinomas

Modern classification schemes divide cervical adenocarcinomas into human papillomavirus (HPV)-associated and HPV-independent types. The precursor lesions of the former are well known and comprise HPV-associated (usual/endocervical) adenocarcinoma in situ (AIS) and the much less common stratified mucin-producing intraepithelial lesion (SMILE). The precursor lesions of HPV-independent cervical adenocarcinomas are much less well known, although postulated precursors of gastric-type adenocarcinoma include atypical lobular endocervical glandular hyperplasia and gastric-type AIS. In this review, we cover HPV-associated and HPV-independent precursor lesions of cervical adenocarcinomas concentrating on diagnostic criteria (morphology and immunophenotype) and differential diagnosis. We propose a uniform terminology and diagnostic criteria for precursor lesions showing intestinal differentiation with goblet cells because this may be a feature of both HPV-associated and HPV-independent AIS.

Characteristic Cytological Findings of Lobular Endocervical Glandular Hyperplasia Associated with Adenocarcinoma of the Uterine Cervix

OBJECTIVE

To investigate the cytological findings of lobular endocervical glandular hyperplasia (LEGH) associated with adenocarcinoma and to clarify its characteristics and the coexisting adenocarcinoma using histochemistry and immunohistochemistry.

METHODS

Eighteen surgical cases of LEGH of the uterine cervix were retrospectively reviewed and classified into 3 groups: pure (pure type), atypical (atypical type), and LEGH with adenocarcinoma (mixed type). The mixed type is defined as LEGH or atypical LEGH with in situ or invasive adenocarcinoma. Cytological findings of conventional endocervical smear specimens (Papanicolaou stain) were analyzed. Histochemistry (periodic acid-Schiff reaction) and immunohistochemistry (M-GGMC-1, Muc-6 glycoprotein, and Ki-67) were performed using tissue specimens.

RESULTS

Cytologically, the pure type (7 cases) is characterized by glandular cell clusters that tended to form monolayered sheets with uniformly small nuclei and contain golden-yellowish mucin, whereas atypical (5 cases) and mixed (6 cases) types are characterized by glandular cell clusters similar to those of the pure type, but with complex glandular structures and mucin localization on the surface of glandular cell clusters. Ki-67 labeling index was significantly higher in atypical and mixed types than that in the pure type. Gastric-type mucinous carcinoma (MC-G) was observed in 2 out of 6 cases with mixed type.

CONCLUSIONS

LEGH is found to be associated with adenocarcinoma types other than MC-G. Complex glandular structures or mucin localization on the surface of glandular cell clusters may be useful cytological findings to detect atypical and mixed types of LEGH.

Gastric-type mucinous carcinoma of the cervix and its precursors - historical overview

The emerging concept of gastric-type mucinous carcinoma (GAS) of the uterine cervix has been accepted worldwide because of its aggressive clinical behaviour and the absence of high-risk human papillomavirus (HPV). GAS is included as a variant of mucinous carcinoma in the 2014 World Health Organization classification, and its recognition has provoked a discussion on endocervical adenocarcinoma as a single entity such that endocervical adenocarcinoma is now divided into HPV-associated and HPV-independent groups. This article reviews historical and conceptual aspects of GAS and its precursors, starting with minimal deviation adenocarcinoma (MDA), through the ensuing confusion, up to the recent paradigm shift in cervical adenocarcinoma subclassification. The gastric immunophenotype of MDA was demonstrated by a Japanese group in 1998 using the HIK1083 antibody, which recognises gastric pyloric gland mucin, and this elucidated the pathogenesis of this particular tumour. However, this information resulted in overdiagnosis of lobular endocervical glandular hyperplasia (LEGH), first described in 1999 and which represents pyloric gland metaplasia (PGM), as malignant. In the early 2000s the relationship between MDA and LEGH/PGM became a matter of controversy. In 2007 HIK1083 immunohistochemistry extended the morphological spectrum of endocervical adenocarcinoma showing gastric differentiation beyond MDA, which resulted in the proposal of GAS as a distinct entity including MDA as its very well-differentiated subtype. GAS is now considered to be an aggressive and chemoresistant neoplasm that is not related to high-risk HPV. The LEGH/PGM-GAS sequence is currently regarded as an HPV-independent pathway of carcinogenesis. Understanding the underlying molecular events in this process is key to the development of biomarkers for early detection and molecular targeted therapy.

Endometrial Gastric (Gastrointestinal)-type Mucinous Lesions: Report of a Series Illustrating the Spectrum of Benign and Malignant Lesions

With the recent elucidation of gastric-type lesions in the female genital tract (especially in the cervix), occasional cases of endometrial adenocarcinoma displaying gastric (gastrointestinal) differentiation have been reported, but they are currently not recognized as a distinct pathologic entity. We report 9 cases of endometrial mucinous lesions which exhibit gastric (gastrointestinal)-type features by morphology and immunohistochemistry, including 4 adenocarcinomas and 5 benign mucinous lesions, in patients aged 32 to 85. The adenocarcinomas showed gastric-type morphology in all 4 cases and goblet cells in 1, with a component of benign gastric-type mucinous glands in 1 case. Immunohistochemically, the adenocarcinomas were positive for CK7 (4/4), CEA (4/4), MUC6 (3/3), PAX8 (3/4), CK20 (2/4), CDX2 (2/4), and estrogen receptor (1/4). They were negative for Napsin A (0/3), with mutation-type p53 staining in 2/4 cases, block-type p16 positivity in 1/4, and scattered chromogranin-positive cells in 1/2. Targeted next-generation sequencing revealed nonsense mutation in RB1 gene for the case with block-positive p16. Follow-up was available in all adenocarcinoma cases and indicated aggressive behavior; 2 patients were dead of disease at follow-up of 7 months to 3 years, 1 was alive with progression at 9 months, and 1 was alive without disease at 7 months. The benign mucinous lesions (including the benign component in 1 adenocarcinoma) exhibited gastric-type morphologic features in 5/6 cases, goblet cells in 5/6, and Paneth-like neuroendocrine cells in 1/6. These benign mucinous lesions were associated with an endometrial polyp in 5/6 cases. Cytologic atypia was present in 2/6 cases and a lobular architecture resembling cervical lobular endocervical glandular hyperplasia in 4/6. Immunohistochemically, the benign mucinous lesions were positive for CK7 (5/5), CDX2 (5/6), estrogen receptor (4/5), MUC6 (4/5), CK20 (3/5), PAX8 (3/5), and CEA (2/4), with scattered chromogranin-positive cells in 4/4 cases; in all cases tested Napsin A was negative, p53 was wild-type and p16 was negative. We propose the term "endometrial gastric (gastrointestinal)-type adenocarcinoma" for this distinctive group of rare aggressive endometrial carcinomas. We believe that benign or atypical gastric (gastrointestinal)-type mucinous lesions are putative precursors for these adenocarcinomas, comparable to recognized premalignant gastric-type lesions in the cervix and the vagina. Future recognition and reporting of these gastric-type endometrial mucinous lesions will help delineate their pathogenesis and clinical significance.

Worsening cytology and lesion enlargement are useful indicators for malignant transformation of lobular endocervical glandular hyperplasia during follow-up: A case report

•

We report a case of MDA arising from clinical LEGH during 5 years of follow-up.

•

The first sign suggesting MDA was cellular atypia in endocervical cytology, and was followed by an increase in tumor size.

•

MDA lesion lacked in stromal reaction and MRI failed to detected MDA.

•

Worsening cytology and lesion enlargement are important signs for malignant change of LEGH during follow-up.

Immunophenotype analysis using CLDN18, CDH17, and PAX8 for the subcategorization of endocervical adenocarcinomas in situ: gastric-type, intestinal-type, gastrointestinal-type, and Müllerian-type

A classification system for invasive endocervical adenocarcinoma (ECA) focusing on high-risk human papillomavirus (HPV) detection has been recently developed. However, precursor lesions of each ECA subtype and immunohistochemical markers that effectively subcategorize ECAs with gastric and intestinal differentiation have not been fully described. Here, we aimed to subcategorize endocervical adenocarcinoma in situ (AIS) by immunophenotype and to characterize the histopathology of each AIS subtype. We immunohistochemically analyzed 36 AIS and 25 lobular endocervical glandular hyperplasia (LEGH) samples using three cell lineage-specific markers (CLDN18, gastric epithelial cells; CDH17, intestinal epithelial cells; and PAX8, Müllerian epithelial cells). The AISs were immunophenotypically classified as gastric-type (G-AIS; n = 2), intestinal-type (I-AIS; n = 10), gastrointestinal-type (GI-AIS; n = 3), Müllerian-type (M-AIS; n = 18), and AIS, not otherwise specified (AIS-NOS; n = 3). All 25 LEGHs were categorized as gastric-type. G-AIS had pale eosinophilic or clear cytoplasm with a small amount of apical mucin and fewer mitotic bodies. I-AIS comprised various numbers of goblet cell-type tumor cells. GI-AIS showed intermediate or mixed features of G-AIS and I-AIS. M-AIS, as with the usual-type ECA, was typically characterized by mucin depletion; however, several lesions had abundant cytoplasmic mucin. High-risk HPV was detected in most AISs but was negative in 100% (2/2) of G-AIS, 10% (1/10) of I-AIS, and 6% (1/18) of M-AIS lesions. In summary, the AIS subtypes defined by immunophenotype had distinct histopathological and etiological characteristics. Thus, immunophenotyping with CLDN18, CDH17, and PAX8 might improve the diagnostic accuracy of histopathological classifications of ECAs.

Molecular characterization of gastric-type endocervical adenocarcinoma using next-generation sequencing

Gastric-type endocervical adenocarcinoma is an uncommon aggressive type of endocervical adenocarcinoma that is not associated with human papillomavirus (HPV). At present, this tumor is classified under the spectrum of mucinous carcinoma of the uterine cervix. The clinical stage of gastric-type endocervical adenocarcinoma at the time of diagnosis is usually more advanced compared to the HPV-associated endocervical adenocarcinoma. Widespread dissemination to unusual sites, such as omentum, peritoneum, and distant organs, can be present. Owing to its rare incidence, diagnostic dilemmas, and aggressive behavior, clinical management can be challenging. In this study, we aimed to elucidate the molecular characteristics of these tumors by using next-generation sequencing (NGS) to assess 161 unique cancer-driver genes for single-nucleotide and copy-number variations, gene fusions, and insertions/deletions within gastric-type endocervical adenocarcinoma tumors. In total, 92 variants were detected across the 14 samples tested (7 variants on average per tumor). TP53 was the most recurrently mutated gene followed by MSH6, CDKN2A/B, POLE, SLX4, ARID1A, STK11, BRCA2, and MSH2. Abnormal p53 expression was observed in nine cases by immunohistochemistry, of which TP53 variants were present in four cases. MDM2 gene amplification in 12q15 (69202190-69233452) locus was seen in two cases that express normal p53 levels by immunohistochemistry. Four cases had STK11 null (frameshift/nonsense) variants, three of which were previously reported in Peutz-Jeghers syndrome. Overall, genes that are implicated in DNA damage, repair, cell cycle, Fanconi anemia pathway, and the PI3K-AKT signaling pathways were found to be mutated. Of note, genes known to have acquired and/or inherited variants in endometrial tumors were enriched within our cohort. In conclusion, our study shows the genetic heterogeneity of gastric-type endocervical adenocarcinoma with some potentially actionable molecular alterations, which highlights the importance of further molecular characterization for better identification of this rare entity, and hence better clinical management.