A Detailed Immunohistochemical Analysis of a Large Series of Cervical and Vaginal Gastric-type Adenocarcinomas

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.

Gastric-type endocervical adenocarcinoma and cervical cytology: Experience at a general hospital and review of the literature

INTRODUCTION

Gastric-type endocervical adenocarcinoma (GAS) is an uncommon type of endocervical adenocarcinoma that is not associated with human papillomavirus infection. This diagnosis is relatively rare and may portend a worse prognosis than usual-type endocervical adenocarcinoma. Subtle morphological features make it an under-recognised diagnostic challenge. Study of the cytological features of individual cases is valuable in order to increase awareness of this entity.

METHODS

The pathology database of our institution was searched for the diagnosis of GAS and all cytological and surgical specimens for each patient were reviewed. The original cytological interpretation was compared to a retrospective central review interpretation. Clinical history and follow-up results were obtained from the electronic medical record.

RESULTS

Four cases of GAS were identified. The findings on initial cervical cytology varied, with GAS found in both patients with negative cervical cytology and those with atypical glandular cells. Cytological findings included endocervical cells arranged in three-dimensional clusters and honeycomb sheets with abundant vacuolar cytoplasm, and in two patients, moderate nuclear atypia with irregular nuclear membranes, coarse chromatin, hyperchromatic nuclei, and prominent nucleoli. In one patient, GAS was incidentally discovered via thorough sampling of a cystic lesion in the superior portion of the endocervical canal.

CONCLUSIONS

GAS is an aggressive human papillomavirus-independent type of endocervical adenocarcinoma with subtle morphological features and, as our study shows, varying clinical presentation. Given the aggressive nature of GAS and the difficulties in initial diagnosis, increased awareness of this entity among pathologists is crucial.

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.

Utility of p16 and HPV testing in oropharyngeal squamous cell carcinoma: An institutional review

In the US, 60% to 80% of oropharyngeal squamous cell carcinomas (OPSCCs) are associated with human papillomavirus (HPV). However, until recently, no consensus existed about when and how to test for HPV in patients with head and neck cancers. We aimed to evaluate the use of p16 and HPV testing at our institution because p16 immunohistochemistry is reportedly a reliable surrogate marker for HPV detection in OPSCCs.

METHODS

We identified all cases at our institution of primary or metastatic squamous cell carcinoma (SCC) of the head and neck with a concurrent p16 immunostain analysis from January 1, 2013, through August 31, 2018. Patient demographic data, tumor characteristics, p16 result, and any HPV result (in situ hybridization and E6 and E7 RNA test) were captured.

RESULTS

We identified 104 patients. Most primary tumors (53/57 [93.0%]) and metastases (40/47 [85.1%]) were positive for p16. Thirty-seven cases (35.6%) had reflex high-risk HPV (HR HPV) testing performed. Of the 35 p16-positive cases, 6 had discrepant HR HPV results (p16⁺ /HPV^- ). We identified 47 p16 immunostains that were performed on lymph nodes with primary tumors of unknown origin. Most were cytology cases (34/47 [72.3%]), and most were p16 positive (40/47 [85.1%]). Neither tumor differentiation nor tumor keratinization was predictive of p16 positivity. Tumors with basaloid differentiation were universally p16 positive.

CONCLUSION

p16 immunohistochemistry accurately identifies HPV-positive OPSCC. Cytology specimens have an important role in characterizing SCC of unknown origin. HR HPV testing is not routinely required, and results may be discrepant with p16 findings.

Cervical adenocarcinoma: integration of HPV status, pattern of invasion, morphology and molecular markers into classification

Cervical adenocarcinoma is a heterogenous group of tumours with various aetiologies, molecular drivers, morphologies, response to treatment and prognosis. It has become evident that human papillomavirus (HPV) infection does not drive all adenocarcinomas, and appropriate classification is critical for patient management, especially in the era of the HPV vaccine and HPV-only screening. Identified as one of the most important developments in gynaecological pathology during the past 50 years, the separation of cervical adenocarcinomas into HPV-associated (HPVA) and HPV-independent has resulted in a transformation of the classification system for cervical adenocarcinomas. HPVA has been traditionally subclassified by morphology, such as usual type (UEA), mucinous and villoglandular, etc. However, it has become evident that cell type-based histomorphological classification is not clinically meaningful, and the newly proposed International Endocervical Adenocarcinoma Criteria and Classification (IECC) is a necessary and relevant break from this prior system. Non-HPV-associated adenocarcinomas can be divided by their distinct morphology and molecular genomics with very different responses to standard therapies and potential for future targeted therapies. These include gastric-type, clear-cell, mesonephric and endometrioid adenocarcinomas. So-called 'serous' carcinomas of the cervix probably represent morphological variants of UEA or drop metastases from uterine or adnexal serous carcinomas, and the existence of true cervical serous carcinomas is in question. This review will discuss the advances since WHO 2014, and how HPV status, pattern of invasion as described by Silva and colleagues, histological features and molecular markers can be used to refine diagnosis and prognostication for patients with cervical adenocarcinoma.

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.

A Comprehensive Review of Biomarker Use in the Gynecologic Tract Including Differential Diagnoses and Diagnostic Pitfalls

Morphologic (ie, hematoxylin and eosin) evaluation of the Mullerian tract remains the gold standard for diagnostic evaluation; nevertheless, ancillary/biomarker studies are increasingly utilized in daily practice to assist in the subclassification of gynecologic lesions and tumors. The most frequently utilized "biomarker" technique is immunohistochemistry; however, in situ hybridization (chromogenic and fluorescence), chromosomal evaluation, and molecular analysis can also be utilized to aid in diagnosis. This review focuses on the use of immunohistochemistry in the Mullerian tract, and discusses common antibody panels, sensitivity and specificity of specific antibodies, and points out potential diagnostic pitfalls when using such antibodies.

A novel group of HPV-related adenocarcinomas of the lower anogenital tract (vagina, vulva, and anorectum) in women and men resembling HPV-related endocervical adenocarcinomas

Human papillomavirus (HPV) is an oncogenic virus associated with the development of several human cancers. Primary vaginal, vulvar, and anal adenocarcinomas are rare and, to date, have rarely been shown to be associated with HPV infection. We report a series of nine HPV-related adenocarcinomas of the lower anogenital tract distal to the cervix. The tumors involved the vagina (4), anorectum (3), and vulva (2). Two of the three anorectal cases involved men. Patients presented with a vulvar or vaginal mass/nodule, painless rectal bleeding, or during screening colonoscopy. Lesions ranged in size from 3.2 to 8.4 cm. The most salient morphologic characteristic was the presence of papillary or villiform/villoglandular architecture in all cases. Tumors displayed features similar to those of usual type high-risk HPV-related endocervical adenocarcinoma, namely, mucinous or mucin-poor (pseudoendometrioid) features or a hybrid of these, with columnar cells with crowded, cigar-shaped to ovoid irregular nuclei. Mitoses (mostly apical) and apoptotic bodies were easily identified. Adenosis was present in two vaginal cases. One anal tumor featured abundant intracytoplasmic mucin that was multivacuolated in some areas imparting a "clear cell"-like appearance. All tumors were diffusely and strongly positive for p16. Seven of seven tested cases were positive for high-risk HPV by in situ hybridization or polymerase chain reaction. Follow-up information, available in five patients, revealed two local recurrences but no tumor related deaths or distant metastases. We report the first well-documented series of HPV-associated primary adenocarcinomas of the vagina, vulva, and anorectum and broaden the spectrum of HPV-related neoplasia involving the lower anogenital tract in both women and men.

A sporadic gastric-type endocervical adenocarcinoma with endometrial involvement and bilateral ovarian metastasis, a case report

•Gastric type endocervical adenocarcinoma (GAS) is rare in the United States.•GAS is an aggressive tumor and can metastasize unusual sites including peritoneal surfaces and adnexa.•Metastatic lesions can mimic benign/borderline mucinous tumors of ovaries.•There is no established standard of care for GAS.•Genetic consultation should be included in patient's management.

Transcriptome profiling of gastric-type endocervical adenocarcinomas identifies key signaling pathways for tumor progression

OBJECTIVE

Gastric-type endocervical carcinoma is a rare entity of carcinoma of the cervix. In contrast to the intestinal type, the gastric type is not related to Human Papilloma Virus (HPV) infection and has been reported to be much more aggressive than the usual type. Oncogenic pathways involved in this poor-prognosis phenotype are largely unexplored.

METHODS

We compared activation of the main signaling pathways involved in cancer progression between the intestinal- (n = 5), gastric- (n = 6) and usual-type (n = 6) adenocarcinomas of the cervix using a targeted transcriptomic approach (expression of 770 genes) on FFPE samples.

RESULTS

We identified a gene-expression signature composed of 11 genes that allows the classification of these endocervical carcinoma as three distinct molecular entities. There were similarities between mucinous endocervical carcinomas (gastric and intestinal types) despite difference in pathogenesis related to HPV infection. Among HPV-related endocervical carcinoma, the intestinal type could be molecularly distinguished from the usual type by high expression of EIF2AK3 and low expression of PPFIBP2 genes, supporting its classification as a distinct entity. Overexpression of TAL1 and S1PR1 genes were characteristic of the gastric type. The usual type was characterized by high expression of occludin and VAV3 genes. Tight junction disruptions might play an essential role in the metastatic potential of mucinous endocervical carcinoma with concomitant loss of OCLN and claudin 4 proteins. An overexpression of NTRK1 transcript was observed in mucinous endocervical carcinomas when compared to the usual type.

CONCLUSIONS

This transcriptomic study identified a signature that supports the classification of endocervical carcinomas as three distinct entities: usual-, intestinal- and gastric-type. It also points out to disruption of tight junctions as a potential mechanism of metastatic dissemination of these rare tumors.

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.

Recent advances in invasive adenocarcinoma of the cervix

Endocervical adenocarcinomas (ECAs) are currently classified according to the 2014 World Health Organization (WHO) system, which is predominantly based on descriptive morphologic characteristics, considers factors bearing minimal etiological, clinical, or therapeutic relevance, and lacks sufficient reproducibility. The 2017 International Endocervical Adenocarcinoma Criteria and Classification (IECC) system was developed by a group of international collaborators to address these limitations. The IECC system separates ECAs into two major groups-those that are human papillomavirus-associated (HPVA) and those that are non-HPV-associated (NHPVA)-based on morphology (linked to etiology) alone, precluding the need for an expensive panel of immunohistochemical markers for most cases. The major types of HPVA ECA include the usual (with villoglandular and micropapillary architectural variants) and mucinous types (not otherwise specified [NOS], intestinal, signet-ring, and invasive stratified mucin-producing carcinoma). Invasive adenocarcinoma NOS is morphologically uninformative, yet considered part of this group when HPV positive. NHPVA ECAs include gastric, clear cell, endometrioid, and mesonephric types. The IECC system is supported by demographic and clinical features (HPVA ECAs develop in younger patients, are smaller, and are diagnosed at an earlier stage), p16/HPV status (almost all HPVA ECAs are p16 and/or HPV positive), prognostic parameters (NHPVA ECAs more often have lymphovascular invasion, lymph node metastases, and are Silva pattern C), and survival data (NHPVA ECAs are associated with worse survival). A move from the morphology-based WHO system to the IECC system will likely provide clinicians with an improved means to diagnose and classify ECAs, and ultimately, to better personalize treatment for these patients.

Difficulties in diagnosis of a minimal deviation adenocarcinoma of uterine cervix diagnosed postoperatively: brief communication and literature review

PURPOSE

Rare minimal deviation adenocarcinoma (MDA) diagnosed postoperatively as incidental finding of a suspicious cervical lesion at laparoscopy, emphasizing it represents a diagnostic challenge mimicking both benign and malignant cervical lesions with often overlapping imaging characteristics-case report and literature review.

CASE PRESENTATION

35-year-old Gravida with primary infertility presented with a suspicious cervical lesion and complained about menorrhagia, hyper-/dysmenorrhea. Clinical examination was unremarkable, transvaginal scan presented a 42 × 38 × 28 mm sized cervical lesion (i.e. fibroid) without hypervascularization. Unexpectedly, the diagnosis of minimal deviation adenocarcinoma in tissue sample taken from suspicious cervical lesion at laparoscopy was revealed in final pathological report. According to suspected early stage of MDA a radical abdominal hysterectomy (PIVER III/IV), bilateral salpingo-oophorectomy, omentectomy, pelvic and para-aortic lymphadenectomy was scheduled. Final histology report confirmed: "MDA", G2, FIGO pT1b1, pN0 (0/23 LN) L0 V0 Pn0 R0.

RESULTS

Ultrasonography may indicate MDA throughout the examination of vascularization/echogenicity with possibility of mimicking benign lesions with similar characteristics. Magnetic resonance imaging shows no pathognomonic signs for MDA. Subsequently, a review of literature was conducted and main factors affecting the prognosis of MDA considering diagnostic tools, clinical stage, histopathological results and surgical protocols were analyzed.

CONCLUSIONS

Minimal deviation adenocarcinoma represents one of rare cervical adenocarcinomas without HPV-association. While it is crucial to differentiate benign from malignant lesions in this subtype, imaging characteristics often overlap and may not provide a specific diagnosis. Therefore, it should be considered in suspicious multicystic cervical lesions and inconclusive PAP-smear. Definitive diagnosis of this subtype should be based on cervical biopsy.

Immunohistochemical expression of HIK1083 and MUC6 in endometrial carcinomas

AIMS

Gastric-type endocervical adenocarcinoma (EA) is characterised by aggressive behaviour and pathogenesis independent of human papillomavirus infection. Because of its morphology and frequent mutation-pattern expression of p53, gastric-type EA may be confused with several types of endometrial carcinoma, particularly in biopsy and curettage specimens. HIK1083 and MUC6 are immunohistochemical markers used to support a diagnosis of gastric-type EA; however, the rates of expression of these markers in endometrial tumours are largely unknown. We therefore aimed to assess the expression of HIK1083 and MUC6 in a cohort of different types of endometrial carcinoma.

METHODS AND RESULTS

Ninety-one endometrial carcinomas (56 endometrioid, 16 clear cell, and 19 serous) from 91 patients treated with hysterectomy were included. A representative tumour block from each case was used for immunohistochemical staining with HIK1083 and MUC6. The percentage of stained cells (0-100%) and average staining intensity (weak, moderate, and strong) were recorded for both markers. None of 91 cases expressed HIK1083. In contrast, 66% (60/91) of cases showed at least focal expression of MUC6; importantly, 54 of 60 (90%) positive cases showed moderate or strong staining. Five of 60 (8%) cases showed MUC6 staining in ≥50% of tumour cells. Endometrioid tumours (49/56, 88%) were more likely to express MUC6 than cases of clear cell (1/16, 6%) or serous (10/19, 53%) carcinoma.

DISCUSSION

Endometrial carcinoma often expresses MUC6. In contrast, HIK1083 is consistently negative, and thus, when positive, is a more reliable marker for distinguishing gastric-type EA from some of its endometrial mimics.

Morphologic Features of Gastric-type Cervical Adenocarcinoma in Small Surgical and Cytology Specimens

Gastric-type cervical adenocarcinoma (GCA) is a human papillomavirus-unassociated, aggressive, chemorefractory tumor. Well-differentiated examples may exhibit bland morphologic appearances, which could potentially lead to misdiagnosis, particularly in limited material. We sought to characterize the morphologic features of GCA in surgical biopsy and cytology specimens. We identified patients with histologic diagnoses of GCA or minimal-deviation adenocarcinoma between 2004 and 2017. Available slides from biopsy, curettage, and cytology specimens were reviewed. Fifty-nine specimens (37 histology, 22 cytology) were reviewed from 23 patients, including histology specimens alone from 6 patients, cytology specimens alone from 4 patients, and both types of specimen from 13 patients. The median patient age was 52 yr (range, 29-83 yr). Biopsies showed well-to-moderately differentiated adenocarcinomas composed of cells with pale or foamy cytoplasm and well-defined cytoplasmic borders. Nuclei exhibited mild-to-moderate pleomorphism with small nucleoli. The diagnosis was challenging in a minority of biopsies in which neoplastic glandular epithelium was scant, fragmented, and/or well differentiated. Cytology slides showed single and crowded clusters of tumor cells with pale, foamy, and/or vacuolated cytoplasm and well-defined cytoplasmic borders. Nuclei were moderately pleomorphic, round to oval with one or more nucleoli. Of 20 submitted biopsies, GCA was suspected by the submitting pathologist in only 5 (25%) cases. Awareness of the morphologic features and use of confirmatory ancillary studies (eg, immunohistochemistry for markers of gastric differentiation and human papillomavirus testing) will allow accurate diagnosis of these aggressive tumors in biopsy and cytology specimens.

Diagnostic Algorithmic Proposal Based on Comprehensive Immunohistochemical Evaluation of 297 Invasive Endocervical Adenocarcinomas

The International Endocervical Adenocarcinoma Criteria and Classification was developed to separate endocervical adenocarcinomas (ECAs) into 2 main categories on the basis of morphology such as human papilloma virus-associated (HPVA) and non-human papilloma virus-associated adenocarcinomas. We aimed to improve the diagnostic accuracy of International Endocervical Adenocarcinoma Criteria and Classification by performing a comprehensive immunohistochemical evaluation and constructing objective immunohistochemical-based algorithms for the classification of these tumors. Tissue microarrays were constructed from 297 of 409 cases used to develop the original classification. Immunostains included p16, p53, estrogen receptor (ER), progesterone receptor, androgen receptor, Vimentin, CK7, CK20, HER2, HIK1083, MUC6, CA-IX, SATB2, HNF-1beta, napsin A, PAX8, CDX2, GATA3, p63, p40, and TTF-1. High-risk human papilloma virus (HR-HPV) was detected by in situ hybridization (ISH) using probes against E6 and E7 mRNA expressed in 18 different virus types. Vimentin, ER, and progesterone receptor were expressed in a significant minority of ECAs, mostly HPVAs, limiting their use in differential diagnosis of endometrioid carcinoma when unaccompanied by HPV-ISH or p16. HR-HPV ISH had superior sensitivity, specificity, and negative and positive predictive values compared with p16, as published previously. HNF-1beta did not have the anticipated discriminatory power for clear cell carcinoma, nor did MUC6 or CA-IX for gastric-type carcinoma. HNF-1beta and napsin A were variably expressed in clear cell carcinoma, with HNF-1beta demonstrating less specificity, as it was ubiquitously expressed in gastric-type carcinoma and in the majority of HPV-associated mucinous (predominantly intestinal-type and invasive ECA resembling stratified mucin-producing intraepithelial lesion [iSMILE]) and usual-type carcinomas. HIK1083 was expressed in nearly half of gastric-type carcinomas, but not in the vast majority of other subtypes. GATA3 was positive in 10% of usual-type adenocarcinomas and in single examples of other subtypes. Rare gastric-type and HPVA mucinous carcinomas displayed HER2 overexpression. Androgen receptor was positive in 6% of usual-type adenocarcinomas. Aberrant p53 expression was found in only 3.6% of usual-type HPVA carcinomas, but it was more prevalent in mucinous (intestinal type and iSMILE) HPVAs and non-human papilloma virus-associates (particularly in gastric-type carcinoma, >50% of cases). The following diagnostic classification algorithms were developed with the above data. Carcinomas without overt cytoplasmic mucin (endometrioid, usual-type endocervical, clear cell, and mesonephric carcinomas) can be subclassified using HR-HPV ISH, ER, and GATA3, whereas carcinomas with easily appreciated cytoplasmic mucin (endometrioid carcinoma with mucinous features, HPVA mucinous, and gastric-type carcinomas) can be subclassified with HR-HPV ISH and ER.

Primary Vaginal Gastric-type Adenocarcinoma and Vaginal Adenosis Exhibiting Gastric Differentiation: Report of a Series With Detailed Immunohistochemical Analysis

So-called gastric-type adenocarcinoma and related premalignant lesions have been characterized in the cervix, but similar lesions are not widely recognized in the vagina. We report a series of 11 vaginal glandular lesions exhibiting gastric differentiation, comprising 5 cases of adenocarcinoma and 6 of adenosis. All cases occurred in adults (aged 33 to 69) with no known history of diethylstilboestrol exposure. The vaginal adenocarcinomas exhibited morphologic features identical to gastric-type adenocarcinoma of the cervix, but 1 case additionally demonstrated basaloid and sarcomatoid components, which have not been previously reported in cervical gastric-type adenocarcinoma. Immunohistochemically, the adenocarcinomas were positive for MUC6 (4/5), PAX8 (3/5), CK7 (5/5), CK20 (1/5), CDX2 (5/5), CA19.9 (5/5), CEA (4/5), CA125 (5/5), and hepatocyte nuclear factor 1β (5/5). p16, estrogen receptor, and Napsin A were negative in all cases tested, whereas p53 exhibited mutation-type staining in 3/5 cases. In all 5 adenocarcinomas, a component of adenosis with benign or atypical nuclear features was identified; the adenosis displayed gastric morphology in 4 cases and tuboendometrial morphology in 1. The 6 cases of pure vaginal adenosis (without associated adenocarcinoma) all contained gastric-type mucinous glands together with tuboendometrial glands in 2 cases. There was focal intestinal differentiation with goblet cells in all 6 cases and neuroendocrine cells with eosinophilic granules in 3. Cytologic atypia was observed in 4/6 cases of pure vaginal adenosis. Immunohistochemically, the gastric-type adenosis (10 cases) was positive for MUC6 (10/10), estrogen receptor (5/10), PAX8 (8/10), CK7 (9/9), CK20 (2/9), CDX2 (5/9), CA19.9 (8/9), CEA (6/9), CA125 (6/9), hepatocyte nuclear factor 1β (10/10), and Napsin A (1/10). p53 exhibited wild-type immunoreactivity in all 10 cases, whereas p16 was negative in all cases tested. Scattered individual chromogranin-positive cells were present in all 5 cases of pure adenosis tested. Follow-up was available in 4 of the adenocarcinoma cases, with 3 patients dead of disease within 1 to 3 years and 1 patient alive with disease at 1 year. The morphologic and immunohistochemical findings in our study suggest a close relationship between vaginal gastric-type adenocarcinoma and adenosis exhibiting gastric differentiation. This probably represents a distinct pathway of vaginal gastric-type carcinogenesis analogous to that occurring in the cervix. We propose that gastric-type adenocarcinoma be recognized as a distinct histologic subtype of vaginal adenocarcinoma while vaginal adenosis of gastric-type represents a novel subtype of adenosis that requires further study to clarify its biological potential.

Fallopian Tube Mucosal Involvement in Cervical Gastric-type Adenocarcinomas: Report of a Series With Discussion of the Distinction From Synchronous In Situ Tubal Lesions

Cervical gastric-type adenocarcinomas are aggressive non-human papillomavirus-related carcinomas with a propensity for extracervical spread, including unusual sites such as the omentum, peritoneum, and ovary. We report 7 cases of cervical gastric-type adenocarcinoma with fallopian tube involvement predominantly in the form of mucosal colonization without underlying invasion. As far as we are aware, this has not been previously described and this report adds to the literature regarding metastatic neoplasms, which may exhibit tubal mucosal involvement and mimic an in situ lesion at this site. In all cases, there was associated ovarian involvement and in 6 of 7 cases, there was endometrial colonization. We speculate that the fallopian tube (and ovarian) involvement is secondary to transuterine spread. Given the occasional occurrence of multifocal gastric-type glandular lesions (benign or malignant) involving different sites in the female genital tract, we discuss the distinction between synchronous independent and metastatic lesions.

Primary endocervical gastric-type adenocarcinoma: a clinicopathologic and immunohistochemical analysis of 23 cases

Background

Endocervical gastric-type adenocarcinoma (GAS) is a rare non-human papillomavirus-associated adenocarcinoma (NHPVA) with morphologic and immunohistochemical features of gastric differentiation. This study aimed to evaluate cytologic and clinicopathological features, differential diagnosis of endocervical GAS.

Methods

A total of 23 patients diagnosed with endocervical GAS/minimal deviation adenocarcinoma (MDA) at Peking University People’s Hospital between 2009 and 2018 were included. Clinical characteristics, cytologic/histopathologic findings, and immunohistochemical results were collected and analyzed.

Results

The average age of patients was 51 years old (range from 28 to 73). Cytologically, tall columnar epithelial cells with pale, foamy or vacuolated cytoplasm were mostly common, followed by well-defined cytoplasmic borders. Fourteen endocervical GAS cases demonstrated mild cytologic atypia, and 9 cases showed moderate to marked cytologic atypia. Ovarian and fallopian tube involvement were identified in 5 and 6 cases, respectively. Immunohistochemically, tumor cells were diffusely positive for CK7, MUC6 and CA-IX, but focally positive for CK20 and CDX2. P16 was negative or patchy positive in most cases and p53 mutation was identified in 12 cases (12/21, 57.1%).

Conclusions

Endocervical GAS shows different morphologic and immunological features from endocervical usual type adenocarcinoma, but it may be difficult to be differentiated from metastatic mucinous adenocarcinoma to cervix due to similar morphology and overlapping immunohistochemical profile. Therefore, awareness of the morphologic features and immunohistochemical profile of GAS will allow pathologists to recognize and accurately diagnose this rare and aggressive entity.

Cervical Glandular Neoplasia: Classification and Staging

Endocervical adenocarcinomas (EAs) account for 25% of all primary cervical carcinomas. Approximately 85% of EAs are driven by high-risk human papillomavirus (HPV) infection, the most common of which is the so-called usual type endocervical adenocarcinomas. Non-HPV-driven subtypes harbor distinct clinicopathologic features and prognosis and have been increasingly recognized in recent years, which has led to efforts to improve classification of EA based on clinically relevant and reproducible criteria. This review discusses a recently proposed classification system, the International Endocervical Adenocarcinoma Criteria and Classification, which uniquely integrates morphology, cause/pathogenesis, and biological behavior of HPV and non-HPV-driven subtypes of EA.

[Focus on mucinous adenocarcinoma of the uterine cervix]

Cancer of the uterine cervix is the fourth most common cancer in women worldwide, and the fourth leading cause of cancer death in women. Squamous cell carcinoma is the first type of cervical cancer (about 75% of cases), and adenocarcinoma the second. Adenocarcinoma of the uterine cervix were redefined in the 2014 WHO classification. Endocervical adenocarcinoma, usual type, is the mose common. Mucinous adenocarcinoma were classified by this classification into different subtypes: gatric type, intestinal type and signet-ring cell type. This literature review shows the caracteristics of these various subtypes of cervical cancer, little known. These are physiopathological, clinical, cytological histological, pronostic caracteristics, and their treatments.

Adenocarcinoma of the uterine cervix: Pathologic features, treatment options, clinical outcome and prognostic variables

Adenocarcinoma accounts for 10-25% of all cervical cancers, and its relative and absolute rate has raised over the past decades. Most, but not all the authors, reported that adenocarcinoma has a greater propensity to lymph node, ovarian and distant metastases and a worse prognosis compared with squamous cell carcinoma. However, whether histologic type is an independent prognostic factor is still a debated issue. Moreover, adenocarcinoma is a very heterogenous disease, including different histological subtypes. Whereas radical hysterectomy and definitive radiotherapy achieve the same clinical outcome in early stage squamous cell carcinoma, surgery seems to obtain better survival compared with definitive radiotherapy in early stage adenocarcinoma. Chemoradiation is the standard treatment for locally advanced cervical cancer regardless of histologic type, although several retrospective studies showed that patients with adenocarcinoma were more likely to die than those with squamous cell carcinoma both before and after concurrent chemoradiation era. The prognostic relevance of biological variables, such as cyclin-dependent kinase inhibitors, p53, cyclooxygenase-2 [COX-2], cell surface tyrosine-kinases and programmed death-ligand [PD-L1], is still under investigation. Palliative chemotherapy is the only treatment option for persistent or recurrent cervical adenocarcinoma not amenable with surgery and radiotherapy. The use of immune checkpoint inhibitors as well as a therapeutic strategy targeting cell surface tyrosine kinases should be adequately explored in this clinical setting.

Guidelines to Aid in the Distinction of Endometrial and Endocervical Carcinomas, and the Distinction of Independent Primary Carcinomas of the Endometrium and Adnexa From Metastatic Spread Between These and Other Sites

In most cases of suspected endometrial neoplasia tumor origin can be correctly assigned according to a combination of clinical, radiologic, and pathologic features, even when the latter are based upon the examination of relatively small biopsy samples. However there are well-recognized exceptions to this rule which continue to create diagnostic difficulty, and sometimes difficulties persist even after the detailed examination of resection specimens. Among the most common problems encountered in practice are the distinction of primary endometrial and primary endocervical adenocarcinomas, and the determination of tumor origin when there is synchronous, multifocal involvement of gynecologic tract sites, for example the endometrium and the ovary. However, accurate diagnosis in these cases is important because this has significant staging, management and prognostic implications. In this review we discuss the value and limitations of key morphologic, immunophenotypic and molecular findings in these diagnostic scenarios.

Cervical Adenocarcinomas: A Heterogeneous Group of Tumors With Variable Etiologies and Clinical Outcomes

Context.—

Cervical adenocarcinomas are a heterogeneous group of tumors with varying morphologies, etiologies, molecular drivers, and prognoses, comprising approximately 25% of all cervical cancers. Unlike cervical squamous cell carcinoma, adenocarcinomas are not uniformly caused by high-risk human papillomavirus (HPV) infection and, therefore, would not necessarily be prevented by the HPV vaccine.

Objective.—

To provide a review of endocervical adenocarcinoma subtypes and, when appropriate, discuss precursor lesions, etiologies, molecular genetics, and ancillary studies within the context of clinical care. Some historical perspectives will also be provided.

Data Sources.—

Data sources included published peer-reviewed literature and personal experiences of the senior author.

Conclusions.—

Endocervical adenocarcinomas are a histologically diverse group of tumors with various causes and molecular drivers, not all related to HPV infection. Distinguishing them has important implications for treatment and prognosis as well as strategies for prevention.

Gastric-type Adenocarcinoma of the Cervix: Tumor With Wide Range of Histologic Appearances

Gastric-type endocervical adenocarcinoma (GAS) is a recently described diagnostic entity originally characterized as a tumor with (1) voluminous cytoplasm that is (2) clear or pale eosinophilic, and (3) cells showing distinct cell borders. Since the initial tumor description there has been accumulating experience that the neoplasm, in addition to classic features, may show a wide spectrum of morphologic appearances. This paper describes and illustrates cases of GAS with focal or diffuse findings that include: densely eosinophilic cytoplasm, foamy cytoplasm, goblet cells, glands with elongated, stratified nuclei, glands with small cuboidal cells, glands with flattened cells, papillary growth, single cell infiltration and infiltration with microcystic elongated and fragmented pattern. All these patterns may bring up a differential diagnosis with other cervical malignancies such as usual, intestinal, endometrioid, clear cell, serous, and mesonephric adenocarcinoma. The paper describes the patterns of immunostaining of respective lesions that may aid in the diagnostic process and summarizes the main points of the differential diagnosis. GAS is associated with somatic and germline STK11 mutations and TP53 mutations but is invariably negative for human papilloma virus when tumor only is tested. It shows variation in incidence between countries. Awareness of the spectrum of morphologic appearances in GAS is important for accurate and confident diagnosis. Correct identification of GAS is important due to its propensity for ovarian and other distant metastases, markedly worse prognosis as compared with usual endocervical adenocarcinoma, and its relative resistance to chemotherapy.

The central role of the pathologist in the management of patients with cervical cancer: ESGO/ESTRO/ESP guidelines

The European Society of Gynaecological Oncology (ESGO), the European Society for Radiotherapy & Oncology (ESTRO) and the European Society of Pathology (ESP) nominated an international multidisciplinary development group consisting of practicing clinicians who have demonstrated leadership and expertise in cervical cancer to produce evidence-based guidelines regarding all aspects of the management of patients with this disease. Herein, we provide a detailed analysis of the pathological reporting of cervical carcinoma specimens, focusing on practical aspects of specimen sampling and on the core pathological data which are critical for patient management.

Chemoresistance of Gastric-Type Mucinous Carcinoma of the Uterine Cervix: A Study of the Sankai Gynecology Study Group

OBJECTIVE

Gastric-type mucinous carcinoma (GAS) is a novel variant of mucinous carcinoma of the uterine cervix, characterized by aggressive clinical behavior and absence of high-risk human papillomavirus. We conducted this study to evaluate the chemosensitivity of GAS compared with that of usual-type endocervical adenocarcinoma (UEA) in patients who had been enrolled in our previous study.

METHODS

Of 52 patients from our previous phase 2 study (SGSG005) of neoadjuvant chemotherapy with docetaxel and carboplatin for stage IB2 to IIB nonsquamous cervical cancer, 47 (stage IB2, 12; stage IIA2, 7; stage IIB, 28) were enrolled in this study with written informed consent. The biopsy specimens before neoadjuvant chemotherapy and surgical specimens after chemotherapy were centrally reviewed based on the updated World Health Organization classification (2014).

RESULTS

Of 47 patients with nonsquamous cell carcinoma, 20 (42.6%) were diagnosed with UEA, 13 (27.7%) with GAS, 12 (25.5%) with adenosquamous carcinoma, and 1 patient each (2%) with small cell carcinoma and serous carcinoma. Consequently, 33 patients, consisting of 20 patients with UEA and 13 patients with GAS, were eligible for the current study. The response rate of GAS was significantly lower than that of UEA (46.2% vs 85.0%, P = 0.048). Of 16 cases of stage II UEA, 11 (68.8%) were downstaged on microscopic examination of postsurgical specimens, but none of the 8 patients with stage II GAS showed any response (P < 0.01). Two inoperative tumors were GAS. With a median follow-up duration of 56 months, the 5-year progression-free and overall survival rates of GAS were significantly worse than those of UEA (38.5% vs 75.0% [P = 0.011] and 36.9% vs 90.0% [P < 0.001], respectively).

CONCLUSIONS

These findings suggest that GAS should be distinguished from UEA by its chemoresistance, necessitating an alternative treatment strategy established for this distinct subtype of endocervical adenocarcinoma.

Tissue-based Immunohistochemical Biomarker Accuracy in the Diagnosis of Malignant Glandular Lesions of the Uterine Cervix: A Systematic Review of the Literature and Meta-Analysis

Immunohistochemistry is widely used to support a pathology diagnosis of cervical adenocarcinoma despite the absence of a systematic review and meta-analysis of the published data. This systematic review and meta-analysis was performed to investigate the sensitivity and specificity of immunohistochemistry biomarkers in the tissue-based diagnosis of cervical adenocarcinoma histotypes compared with normal endocervix and benign glandular lesions. The systematic review and meta-analysis used a PICOT framework and QUADAS-2 to evaluate the quality of included studies. The literature search spanned 40 years and ended June 30, 2015. Abstracts of identified records were independently screened by 2 of the authors who then conducted a full-text review of selected articles. Sensitivity and specificity of immunohistochemistry expression in malignant glandular lesions of the cervix classified per WHO 2003 compared with 5 benign comparators (normal/benign endocervix, and benign endocervical, endometrioid, gastric, and mesonephric lesions) were calculated. Of 902 abstracts screened, 154 articles were selected for full review. Twenty-five articles with results for 36 biomarkers were included. The only biomarker with enough studies for a meta-analysis was p16 and the definition of positive p16 staining among them was variable. Nevertheless, any positive p16 expression was sensitive, ranging from 0.94 to 0.98 with narrow confidence intervals (CIs), for adenocarcinoma in situ (AIS) and mucinous adenocarcinomas in comparison with normal/benign endocervix and benign endocervical and endometrioid lesions. Specificity for AIS and mucinous adenocarcinomas was also high with narrow CIs compared with benign endocervical lesions. The specificity was high for AIS, 0.99 (0.24, 1.0), and mucinous adenocarcinoma, 0.95 (0.52, 1.0), compared with normal/benign endocervix but with wider CIs, and low with very wide CIs compared with benign endometrioid lesions: 0.31 (0.00, 0.99) and 0.34 (0.00, 0.99), respectively. Results from single studies showed that p16, p16/Ki67 dual stain, ProExC, CEA, ESA, HIK1083, Claudin 18, and ER loss in perilesional stromal cells were useful with high (≥0.75) sensitivity and specificity estimates in ≥1 malignant versus benign comparisons. None of the biomarkers had highly useful sensitivity and specificity estimates for AIS, mucinous adenocarcinomas, or minimal deviation adenocarcinoma/gastric adenocarcinoma compared with benign gastric or mesonephric lesions or for mesonephric carcinoma compared with normal/benign endocervix, benign endocervical, endometrial, or mesonephric lesions. Any expression of p16 supports a diagnosis of AIS and mucinous adenocarcinomas in comparison with normal/benign endocervix and benign endocervical lesions. The majority of studies did not separate mosaic/focal p16 staining from diffuse staining as a distinct pattern of p16 overexpression and this may have contributed to the poor performance of p16 in distinguishing AIS and mucinous adenocarcinomas from benign endometrioid lesions. Single studies support further investigation of 8 additional biomarkers that have highly useful sensitivity and specificity estimates for ≥1 malignant glandular lesions compared with ≥1 of the 5 benign comparators.

Clear Cell Carcinoma of the Cervix With Choriocarcinomatous Differentiation: Report of an Extremely Rare Phenomenon Associated With Mismatch Repair Protein Abnormality

The presence of trophoblastic differentiation or nongestational choriocarcinoma in a carcinoma is rare but has been described in various organs, including in the female genital tract. We report a cervical clear cell carcinoma admixed with a component of choriocarcinoma in a 52-year-old woman, only the second report of this combination in the literature. Immunohistochemically, the tumor exhibited isolated loss of staining with the mismatch repair protein MSH6. We review the literature on trophoblastic differentiation in cervical carcinoma.

International Endocervical Adenocarcinoma Criteria and Classification (IECC): A New Pathogenetic Classification for Invasive Adenocarcinomas of the Endocervix

We sought to classify endocervical adenocarcinomas (ECAs) based on morphologic features linked to etiology (ie, human papillomavirus [HPV] infection), unlike the World Health Organization 2014 classification. The International Endocervical Adenocarcinoma Criteria and Classification (IECC criteria), described herein, distinguishes between human papillomavirus-associated adenocarcinoma (HPVA), recognized by the presence of luminal mitoses and apoptosis seen at scanning magnification, and no or limited HPVA features (nonhuman papillomavirus-associated adenocarcinoma [NHPVA]). HPVAs were then subcategorized based on cytoplasmic features (mostly to provide continuity with preexisting classification schemes), whereas NHPVAs were subclassified based on established criteria (ie, gastric-type, clear cell, etc.). Complete slide sets from 409 cases were collected from 7 institutions worldwide. Tissue microarrays representing 297 cases were constructed; immunohistochemistry (p16, p53, vimentin, progesterone receptor) and chromogenic in situ hybridization using an RNA-based probe set that recognizes 18 varieties of high-risk HPV were performed to validate IECC diagnoses. The 5 most common IECC diagnoses were usual-type (HPVA) (73% of cohort), gastric-type (NHPVA) (10%), mucinous adenocarcinoma of HPVA type, including intestinal, mucinous not otherwise specified, signet-ring, and invasive stratified mucin-producing carcinoma categories (9%), clear cell carcinoma (NHPVA) (3%) and adenocarcinoma, not otherwise specified (2%). Only 3 endometrioid carcinomas were recognized and all were NHPVA. When excluding cases thought to have suboptimal tissue processing, 90% and 95% of usual-type IECC cases overexpressed p16 and were HPV, whereas 37% and 3% of NHPVAs were p16 and HPV, respectively. The 1 HPV gastric-type carcinoma was found to have hybrid HPVA/NHPVA features on secondary review. NHPVA tumors were larger and occurred in significantly older patients, compared with HPVA tumors (P<0.001). The high-risk HPV chromogenic in situ hybridization probe set had superior sensitivity, specificity, and positive and negative predictive values (0.955, 0.968, 0.992, 0.833, respectively) compared with p16 immunohistochemistry (0.872, 0.632, 0.907, 0.545, respectively) to identify HPV-related usual carcinoma and mucinous carcinoma. IECC reliably segregates ECAs into HPVA and NHPVA types using morphology alone. This study confirms that usual-type ECAs are the most common type worldwide and that mucinous carcinomas comprise a mixture of HPVA and NHPVA, with gastric-type carcinoma being the major NHPVA type. Endometrioid and serous carcinomas of the endocervix are extraordinarily rare. Should clinical outcomes and genomic studies continue to support these findings, we recommend replacement of the World Health Organization 2014 criteria with the IECC 2017.

Uncommon hereditary gynaecological tumour syndromes: pathological features in tumours that may predict risk for a germline mutation

The most common hereditary gynaecological tumour syndromes are hereditary breast and ovarian cancer syndrome and Lynch syndrome. However, pathologists also may encounter gynaecological tumours in women with rare hereditary syndromes. Many of these tumours exhibit distinctive gross and microscopic features that are associated with a risk for an inherited gene mutation. The sensitivity and specificity of these tumour pathology features for predicting an inherited mutation vary depending on the syndrome. By recognising these tumour features, pathologists may potentially contribute to the diagnosis of an unsuspected syndrome by recommending referral of the patient for formal risk assessment by genetic counselling. Patients additionally benefit from diagnosis of an inherited syndrome because many also carry a lifetime risk for developing primary malignancies outside of the gynaecological tract. Early diagnosis of an inherited syndrome permits early screening, detection, and management of additional malignancies associated with the syndrome. This review highlights these rare syndromes and their tumour pathology, including Peutz-Jeghers syndrome (gastric type mucinous carcinoma of the cervix; ovarian sex cord tumour with annular tubules); hereditary leiomyoma renal cell carcinoma syndrome (uterine leiomyoma); tuberous sclerosis complex (uterine PEComa; uterine lymphangioleiomyomatosis); DICER1 syndrome (ovarian Sertoli-Leydig cell tumour; cervical embryonal rhabdomyosarcoma); rhabdoid tumour predisposition syndrome 2 (small cell carcinoma of the ovary, hypercalcaemic type); Cowden syndrome (endometrial endometrioid adenocarcinoma); naevoid basal cell carcinoma syndrome (ovarian fibroma); and Von Hippel-Lindau syndrome (clear cell papillary cystadenoma of the broad ligament).

Comprehensive Clinicopathologic and Updated Immunohistochemical Characterization of Primary Ovarian Mucinous Carcinoma

The distinction of primary mucinous ovarian carcinoma (PMOC) from other primaries or secondaries is essential for selecting therapeutic options and prognostication. We aimed to characterize the immunohistochemical profile of 36 PMOCs using an extended immunohistochemical panel, with clinicopathologic features and outcome. PAX8 was negative in 30 (83.3%), and SATB2 was negative in 32/35. HNF1B, AMACR, and napsin-A were detected in 33 (91.7%), 35 (97.2%), and 0 (0%), respectively. MMR proteins and ARID1A were retained in 100%; PTEN was lost in 4 (11.1%). P53 was aberrant in 10 (27.8%); none overexpressed p16. HER2 was positive in 6/35 (17.1%). Most PMOCs had a favorable outcome. However, recurrence is usually fatal. The typical tumor profile was CK7+, CK20+/-, CDX2+/-, PAX8-, ER-, PgR-, and SATB2-. HER2 positivity suggests a possible target for therapy in advanced disease.

Gastric-Type Endometrial Adenocarcinoma: Report of Two Cases in Patients From the United States

Gastric-type adenocarcinomas of the uterine cervix have been described within the literature in detail; however, the description of gastric-type endometrial adenocarcinomas is a recent development, with only two cases originating from Japan in the world literature to date. According to these prior reports, the recognition of this pattern of differentiation is critical, as it is often associated with deep myoinvasion, positive regional lymph nodes, and poor outcome despite appropriate adjuvant treatment. We present two cases of endometrial adenocarcinoma with gastric-type differentiation in patients from the United States with superficial myoinvasion and positive patient outcomes. Gastric-type differentiation in endometrial adenocarcinomas is rare and likely underrecognized. Continued reporting of these cases is necessary to further understand the natural history and clinical implications of this entity.

Meta analysis: HPV and p16 pattern determines survival in patients with HNSCC and identifies potential new biologic subtype

Consistent discrepancies in the p16/HPV-positivity have been observed in head and neck squamous cell carcinoma (HNSCC). It is therefore questionable, if all HPV+ and/or p16+ tested cancers are HPV-driven. Patients down-staged according to the HPV-dependant TNM are at risk for undertreatment and data in clinical trials may be skewed due to false patient inclusion. We performed a meta-analysis to classify clinical outcomes of the distinct subgroups with combined p16 and HPV detection. 25 out of 1677 publications fulfilled the inclusion criteria. The proportion of the subgroups was 35.6% for HPV+/p16+, 50.4% for HPV-/p16-, 6.7% for HPV-/p16+ and 7.3% for HPV+/P16-. The HPV+/p16+ subgroup had a significantly improved 5-year overall-survival (OS) and disease-free-survival in comparison to others both for HNSCC and oropharyngeal cancers. The 5-year OS of the HPV-/p16+ HNSCC was intermediate while HPV+/p16- and HPV-/p16- had the shortest survival outcomes. The clearly distinct survival of HPV-/p16+ cancers may characterize a new relevant HPV-independent subtype yet to be biologically characterized. The possibility also exists that in some HPV+/p16+ cancers HPV is an innocent bystander and p16 is independently positive. Therefore, in perspective, HPV-testing should distinguish between bystander HPV and truly HPV-driven cancers to avoid potential undertreatment in HPV+ but non-HPV-driven HNSCC.

Diagnostic immunohistochemistry in gynaecological neoplasia: a brief survey of the most common scenarios

Immunohistochemistry is a valuable adjunct in routine gynaecological pathology. The molecular revolution has redesigned knowledge of gynaecological cancers and refined histological classification. The direct consequence has been the progressive introduction of new immunostainings for diagnostic and classification purposes. Hence, we review the routine diagnostic use of immunohistochemistry in the field of gynaecological neoplasia. We reviewed the immunomarkers useful in gynaecological pathology according to literature revision, our personal experience and research findings. We discuss the application of immunohistochemistry to reach the most accurate diagnosis in morphologically equivocal cases of gynaecological pathology and present the appropriate panel of immunomarkers in the most common scenarios of gynaecological pathology. This short review provides an updated overview of the essential immunohistochemical markers currently used in the diagnostics of gynaecological malignancies along with their molecular rationale.

Immunohistochemistry in Gynecologic Pathology: An Example-Based Practical Update

CONTEXT

- Immunohistochemical stains are routinely applied in the pathology diagnostic workup of gynecologic lesions. The rapidly expanding repertoire of available markers helps in refining the diagnostic criteria for each disease entity; however, limitations and pitfalls exist.

OBJECTIVE

- To provide a practical, relevant update on the use of immunohistochemistry for commonly encountered differential diagnoses in gynecologic pathology.

DATA SOURCES

- Literature review and authors' diagnostic experience.

CONCLUSIONS

- Immunohistochemistry is a helpful adjunct tool in gynecologic pathology. Although the primary application is in the diagnostic workup, novel prognostic and predictive markers, and immunostains to screen for genetic cancer syndromes, have also been recently introduced in the field.

HPV-negative Gastric Type Adenocarcinoma In Situ of the Cervix: A Spectrum of Rare Lesions Exhibiting Gastric and Intestinal Differentiation

In recent years, a number of benign and malignant cervical glandular lesions exhibiting gastric differentiation have been described but premalignant gastric-type lesions have not been well characterized. We report a series of 9 cases of a rare form of cervical adenocarcinoma in situ (AIS) distinguished by gastric and sometimes intestinal differentiation and lack of association with human papillomavirus (HPV) infection. The lesions occurred in women aged 25 to 73 years (mean age 51 y). All cases were located at (or just proximal to) the cervical transformation zone and there was extension to the lower uterine segment in 3 cases, 2 of which also involved the endometrium. In all cases, the normal cervical glandular architecture was largely preserved but in 5 cases there was a mild degree of increased intraglandular architectural complexity. The glandular epithelium ranged from almost purely gastric in type (4 cases) to mixed gastric and intestinal (5 cases), with varying proportions of intermixed goblet cells. In contrast to the basophilic cytoplasm of normal endocervical glands, the gastric-type epithelium was typically predominantly composed of cells with eosinophilic or pale pink cytoplasm, but conspicuous foamy or clear cell cytoplasm was present in some cases. Nuclear atypia was present in all cases but was considered low-grade in 8. High-grade features such as marked nuclear pleomorphism and hyperchromasia were evident in only 1 case. Mitotic activity and apoptotic bodies were present but both were noted to be less frequent than in usual type (HPV-related) AIS. Immunohistochemically, there was usually positive staining with CK 7 (7/7 cases) and MUC 6 (7/8 cases) and some cases were positive with CK 20 (3/7), CDX2 (5/9), PAX 8 (5/9) and CEA (2/6). Estrogen receptor and progesterone receptor were usually negative, although Estrogen receptor was positive in 3 of 9 cases. p16 was negative or exhibited mosaic-type staining (nonblock staining) in all cases and there was mutation-type p53 staining in 2 of 9 cases. HPV molecular testing was negative in all 4 cases tested. We believe this unusual subtype of AIS, which we term "gastric-type AIS (gAIS)," represents a precursor to gastric-type adenocarcinoma of the cervix and suggest that gAIS and so-called "atypical lobular endocervical glandular hyperplasia" are related entities within a spectrum of premalignant gastric-type lesions for which we propose the umbrella term gAIS. The malignant potential and optimal management of gAIS are currently unknown but in one of our cases a gastric-type adenocarcinoma developed 6 years after removal of a cervical polyp which contained gAIS. The introduction of HPV vaccination will result in a relative increase in incidence of premalignant and malignant cervical glandular lesions exhibiting gastric differentiation and these will not be detected by HPV-based screening programs.

Cervical Adenocarcinoma: Diagnosis of Human Papillomavirus-Positive and Human Papillomavirus-Negative Tumors

CONTEXT

- Cervical adenocarcinomas span a diverse group of tumors with several distinct histologic tumor types, which include endocervical, endometrioid, intestinal, villoglandular, gastric, signet ring, serous, clear cell, and mesonephric. Diagnosis of cervical adenocarcinoma, especially early diagnosis, poses a significant challenge.

OBJECTIVE

- To review the pathogenesis, diagnostic criteria, immunohistochemical markers, and differential diagnosis of various subtypes of human papillomavirus (HPV)-positive and HPV-negative cervical adenocarcinomas. The paper presents a concise summary of the issues that may be particularly difficult in histopathologic diagnosis, such as differentiating neoplastic lesions from benign mimics, determining the tumor type, differentiating early invasive lesions from adenocarcinoma in situ, measuring the depth of invasion, and, finally, differentiating primary cervical adenocarcinoma from uterine endometrioid adenocarcinoma and tumors metastatic from other primary sites.

DATA SOURCES

- The study employed a PubMed search of recently published reports.

CONCLUSIONS

- Early detection of HPV-positive tumor types may be aided with the expansion of HPV testing; however, early diagnosis of HPV-negative cervical adenocarcinomas will continue to pose a challenge and may require the development of additional molecular testing techniques.