Micropapillary Cervical Adenocarcinoma: A Clinicopathologic Study of 44 Cases

A Population-based Study Investigating the Incidence of Human Papillomavirus-Associated and Human Papillomavirus-Independent Cervical Adenocarcinomas

Cervical adenocarcinomas are now classified as human papillomavirus (HPV)-associated and HPV-independent types with the former being more common. However, population-based studies regarding the relative incidences of the 2 types are few. This study investigates the incidence of cervical adenocarcinomas in Northern Ireland (a country with a relatively stable population of ~1.8 million) over a recent 9-year period (2015-2023). Overall, there were 146 primary cervical adenocarcinomas, 130 HPV-associated (89%) and 16 HPV-independent (11%). The median age was 43 years (range: 24-82) for HPV-associated and 62.5 years (range: 31-84) for HPV-independent neoplasms; this was statistically significant (P < 0.001). The calculated age-adjusted incidence of the patients with HPV-associated and HPV-independent neoplasms was 1.68 and 0.20 per 100,000 person-years, respectively. The HPV-independent neoplasms were more often advanced stage at diagnosis; 97 of 130 (75.4%) of the HPV-associated cases were diagnosed at Stage I compared with 5 of 16 (31.3%) of the HPV-independent cases. The HPV-independent neoplasms were mostly gastric-type (56.3%) with smaller numbers of clear cells and mesonephric. Despite the relatively short follow-up, the mortality of patients with HPV-independent adenocarcinomas was significantly higher than patients with HPV-associated neoplasms (56.3% vs 5.4%) with a median survival of just over a year (13.2 mo) in the former for those who died.

State of the art of cervical cancer treatment in rare histologies

The objective of this review is to summarize the current scientific evidence to formulate clinical recommendations regarding the classification, diagnostic approach, and treatment of rare histological subtypes of cervical cancer; neuroendocrine carcinoma, gastric-type mucinous adenocarcinoma, and glassy cell adenocarcinoma. These histological subtypes are generally characterized by their low frequency, aggressive biological behavior, certain chemoradioresistance, and consequently, high recurrence rates with a deleterious impact on survival. Molecular studies have identified several associated mutations in neuroendocrine carcinoma (PIK3CA, MYC, TP53, PTEN, ARID1A, KRAS, BRCA2) and gastric-type adenocarcinoma (KRAS, ARID1A, PTEN) that may serve as molecular targets. While adenocarcinomas are typically treated and classified based on squamous histology across early, locally advanced, and advanced stages, the treatment strategies for neuroendocrine carcinomas in early stages or locally advanced cases differ, particularly in the sequencing of administering chemotherapy, chemoradiotherapy, or surgery. The chemotherapy regimen is based on etoposide plus cisplatin (EP). Unlike squamous cell carcinomas, immune checkpoint inhibitors are yet to establish a standard role in the treatment of recurrent neuroendocrine carcinomas due to the absence of clinical trials. Regarding glassy cell adenocarcinomas and gastric-type adenocarcinoma, the potential use of immunotherapy in advanced stages/disease requires further evaluation through international collaborations, given the limited number of cases.

Invasive Squamous Cell Carcinoma of the Cervix: A Review of Morphological Appearances Encountered in Human Papillomavirus-associated and Papillomavirus-independent Tumors and Precursor Lesions

Cervical cancer is the fourth most common cancer among women globally. Historically, human papillomavirus (HPV) infection was considered necessary for the development of both precursor and invasive epithelial tumors of the cervix; however, studies in the last decade have shown that a significant proportion of cervical carcinomas are HPV-independent (HPVI). The 2020 World Health Organization (WHO) Classification of Female Genital Tumors separates both squamous cell carcinomas (SCCs) and endocervical adenocarcinomas (ECAs) by HPV status into HPV-associated (HPVA) and HPVI tumors. The classification further indicates that, in contrast to endocervical adenocarcinomas, HPVI and HPVA SCCs cannot be distinguished by morphological criteria alone and suggests that HPV testing or correlates thereof are required for correct classification. Moreover, while HPVA SCC precursor lesions (ie, high-grade squamous intraepithelial lesion) are well known and characterized, precursors to HPVI SCCs have only been described recently in a small number of cases. We studied 670 cases of SCCs from the International Squamous Cell Carcinoma Project (ISCCP) to analyze the reproducibility of recognition of invasive SCC growth patterns, presence of lymphovascular space invasion, tumor grade, and associations with patient outcomes. Consistent with previous studies, we found histologic growth patterns and tumor types had limited prognostic implications. In addition, we describe the wide morphologic spectrum of HPVA and HPVI SCCs and their precursor lesions, including tumor growth patterns, particular and peculiar morphologic features that can lead to differential diagnoses, and the role of ancillary studies in the diagnosis of these tumors.

Predicting Lymph Node Metastasis From Primary Cervical Squamous Cell Carcinoma Based on Deep Learning in Histopathologic Images

We developed a deep learning framework to accurately predict the lymph node status of patients with cervical cancer based on hematoxylin and eosin-stained pathological sections of the primary tumor. In total, 1524 hematoxylin and eosin-stained whole slide images (WSIs) of primary cervical tumors from 564 patients were used in this retrospective, proof-of-concept study. Primary tumor sections (1161 WSIs) were obtained from 405 patients who underwent radical cervical cancer surgery at the Fudan University Shanghai Cancer Center (FUSCC) between 2008 and 2014; 165 and 240 patients were negative and positive for lymph node metastasis, respectively (including 166 with positive pelvic lymph nodes alone and 74 with positive pelvic and para-aortic lymph nodes). We constructed and trained a multi-instance deep convolutional neural network based on a multiscale attention mechanism, in which an internal independent test set (100 patients, 228 WSIs) from the FUSCC cohort and an external independent test set (159 patients, 363 WSIs) from the Cervical Squamous Cell Carcinoma and Endocervical Adenocarcinoma cohort of the Cancer Genome Atlas program database were used to evaluate the predictive performance of the network. In predicting the occurrence of lymph node metastasis, our network achieved areas under the receiver operating characteristic curve of 0.87 in the cross-validation set, 0.84 in the internal independent test set of the FUSCC cohort, and 0.75 in the external test set of the Cervical Squamous Cell Carcinoma and Endocervical Adenocarcinoma cohort of the Cancer Genome Atlas program. For patients with positive pelvic lymph node metastases, we retrained the network to predict whether they also had para-aortic lymph node metastases. Our network achieved areas under the receiver operating characteristic curve of 0.91 in the cross-validation set and 0.88 in the test set of the FUSCC cohort. Deep learning analysis based on pathological images of primary foci is very likely to provide new ideas for preoperatively assessing cervical cancer lymph node status; its true value must be validated with cervical biopsy specimens and large multicenter datasets.

Distinct histopathological features are associated with molecular subtypes and outcome in low grade serous ovarian carcinoma

Low grade serous ovarian carcinoma (LGSOC) demonstrates unique clinical and molecular features compared to other ovarian cancer types. The relationship between common histological features of LGSOC and molecular events, such as hormone receptor expression patterns and MAPK gene mutation status, remains poorly understood. Recent data suggest some of these molecular features may be biomarkers of response to recently introduced biologically-targeted therapies, namely endocrine therapy and MEK inhibitors. We utilize a cohort of 63 pathologically-confirmed LGSOC cases with whole exome sequencing and hormone receptor expression data to investigate these relationships. LGSOC cases demonstrated uniformly high oestrogen receptor (ER) expression, but variable progesterone receptor (PR) expression intensity. 60% and 37% of cases demonstrated micropapillary and macropapillary patterns of stromal invasion, respectively. 63% of cases demonstrated desmoplasia, which was significantly associated with advanced disease stage and visible residual disease after cytoreductive surgery. MAPK-mutant cases (KRAS, BRAF, NRAS) more frequently demonstrated macropapillary stromal invasion, while Chr1p loss was associated with desmoplasia and low PR expression. Presence of micropapillary stromal invasion and low PR expression were associated with significantly poorer survival after accounting for stage and residual disease status. Together, these data identify novel relationships between histopathological features and molecularly-defined subgroups in LGSOC.

Villoglandular Pattern in HPV-associated Endocervical Adenocarcinoma is Associated With Excellent Prognosis: A Reappraisal of 31 Cases Using IECC and Silva Pattern Classification

Villoglandular adenocarcinoma of the cervix is a rare histologic entity that typically develops in young women, characterized by an association with oral contraceptives and excellent prognosis, though this point is controversial. These tumors have not been studied in the context of the International Endocervical Adenocarcinoma Criteria and Classification (IECC) or Silva Pattern Classification. We analyzed 31 cases that met strict diagnostic criteria, including being completely excised with negative margins. These were categorized according to IECC and Silva Pattern Classification and the association with various pathologic parameters analyzed. Most patients were young with a mean age of 41.1 (range 25-79). There were 14 (45.2%) pattern A, 11 (35.5%) pattern B, and 6 (19.3%) pattern C cases. Only 1 of 22 patients (4.5%) presented with lymph node metastasis at the time of diagnosis (pattern C, stage IB1) and 3 (9.7%) had lymphovascular invasion (2 pattern C, 1 pattern B). Overall survival was 100%, while recurrence-free survival was 96.2% for the entire cohort with only 1 case (3.2%) recurring 25 mo after surgery (IB2, pattern B). Kaplan Meier analysis (log rank test) revealed no significant correlation for recurrence-free survival at 5 and 10 yr associated with depth of invasion, tumor size, Silva pattern, FIGO stage, lymphovascular invasion, or lymph node metastasis. Cox univariate analysis demonstrated no independent prognostic factors predicting recurrence-free survival. These results indicate that completely excised villoglandular adenocarcinoma generally has an excellent prognosis and when Silva Pattern Classification is applied, those tumors that potentially have a higher chance for adverse outcomes can be identified.

Expression of autocrine motility factor receptor (AMFR) in human breast and lung invasive micropapillary carcinomas

The aim of this study was to evaluate the clinicopathological significance of autocrine motility factor receptor (AMFR) expression in a variety of human invasive micropapillary carcinomas (IMPC). AMFR expression was compared in 111 samples of a variety of human IMPCs which had intrinsic non-micropapillary components and with 26 cases of control pulmonary adenocarcinoma (CPA, carcinoma without an IMPC component) by immunohistochemistry (IHC). In the 137 cases analysed, AMFR expression was significantly elevated in the IMPC components compared to the non-IMPC components (p = .005) and normal tissues (p < .001). AMFR expression was also higher in the IMPC samples compared to their intrinsic non-IMPC components (p = .0234). Between the 69 cases of lung IMPC and 26 cases of CPA, AMFR expression was notably higher in the IMPC components than in the CPA components (p = .0455). However, there was no significant difference between the non-IMPC components in the lung and the CPA components (p = .4584). Moreover, in breast cancer, elevated AMFR expression was not significantly correlated with mixed type or pure type IMPC (p = .5969) or with age, gender, T stage, or lymph node metastasis (LNM). Between IMPC and CPA of the lung, there was no statistical significance in age, T stage, and LNM, where AMFR expression was higher in IMPC (p = .0071). Thus this study demonstrated that AMFR was overexpressed in a variety of human IMPC components compared with non-micropapillary components. This suggests that AMFR expression is a potential new prognostic indicator for different types of human IMPC, which might thus be a new therapeutic target.

The study of clinicopathologic features of cervical squamous carcinoma with invasive micropapillary like pattern and phenotype

Invasive micropapillary carcinoma has been reported in the adenocarcinoma of many organs including cervix, and many studies have proved it has more invasive biological behavior. This study, for the first time, reports cervical squamous carcinoma with invasive micropapillary like pattern and phenotype (IMLPP) and further investigates its clinicopathologic features. Cervical squamous carcinoma with IMLPP was selected by histological characteristics and immunohistochemical staining. All patients' clinical information and pathological parameters were collected. Based on histological characteristics and immunohistochemical staining results, 24 cases, out of 104 cases of cervical squamous carcinoma, were identified as having invasive micropapillary like pattern. The staining of all 24 cases with EMA and MUC-1 showed the feature of "reverse polarity like". Meanwhile, patient age at diagnosis (P=0.011), maximum invasion depth (P=0.001), maximum diameter (P=0.015), lymphvascular space invasion (P<0.001), pelvic lymph node metastasis (P<0.001), metastasis (P=0.020), death (P=0.025) and FIGO stages (P=0.001) were related to the existence of IMLPP, independently of the proportion of IMLPP to the whole tumor in size. Univariate and multivariate disease-free survival analyses (follow-up time >12 months) showed significant statistical difference between cervical squamous carcinoma with or without IMLPP (P=0.016, P=0.043). Results from our study suggested that IMLPP may be associated with aggressive biological behavior in cervical squamous carcinoma. Therefore, pathologists should pay attention to the existence of it, no matter its proportion with relation to the whole tumor, and bring it to the attention of clinicians.

Infection status and survival impact of high-risk human papillomavirus in cervical adenocarcinomas: A systematic review and meta-analysis

OBJECTIVE

Cervical adenocarcinoma (CAC) comprises a heterogeneous group of tumors that are not universally associated with HPV infection. As has been shown in other organs, it is becoming increasingly apparent that HPV status significantly affects the prognosis of adenocarcinoma. We conducted a systematic review and meta-analysis to investigate the infection status of high-risk Human papillomavirus (hrHPV) in CAC and evaluate its impact on the survival of patients.

METHODS

PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), International Clinical Trials Registry Platform (ICTRP), and Clinical Trials.gov were searched from inception to May 1st, 2022. Data on HPV infection status and survival outcomes were evaluated using STATA 16.0.

RESULTS

Seventy-one studies with 11,278 participants were included in HPV infection analysis and eight studies with 1099 participants were included in prognosis analysis. The HPV infection rate (including high-risk and low-risk) and hrHPV infection rate in CAC were 75% (95% CI 0.70-0.80, 6978 participants) and 75% (95% CI 0.70-0.81, 4906 participants), respectively. HPV-16 and -18 were the most common HPVs in CAC, with pooled infection rates of 37% (95% CI 0.33-0.41, 7848 participants) and 34% (95% CI 0.30-0.38, 7730 participants), respectively. hrHPV infection was associated with better overall survival (HR 0.23, 95% CI 0.11-0.47, 1013 participants), better disease-free survival (HR 0.18, 95% CI 0.07-0.43, 292 participants), better progression-free survival (HR 0.20, 95% CI 0.08-0.47, 271 participants) and less recurrence (RR 0.30, 95% CI 0.07-0.43, 181 participants).

CONCLUSION

HPV infection rates were high in CAC. HPV-16 and -18 had the highest infection rates in CAC. However, hrHPV infection was associated with better survival and less recurrence. Future studies should clarify the relationship between hrHPV infection and other prognostic factors and make reasonable treatment strategies for CAC with different HPV status.

PROTOCOL REGISTRATION

CRD42022319390.

[Revised German guidelines on the diagnosis and treatment of carcinoma of the uterine cervix-what's new for pathologists in 2021?]

In 2021, the 2015 German consensus guideline for the diagnosis and treatment of uterine cervical carcinoma was updated. The present article summarises the new recommendations for pathologists: the incorporation of the International Endocervical Adenocarcinoma Classification (IECC), which morphologically separates HPV-associated and non-HPV-associated adenocarcinomas, as well as the reporting of the prognostic relevant growth pattern of the adenocarcinoma of the endocervical subtype (Silva pattern). Histologically, multifocality has been defined as the presence of clearly invasive foci with a minimum distance between each focus of 0.2 cm. Because of its intratumoural heterogeneity, all carcinomas ≤ 2 cm in their largest dimension should be processed completely, and tumours > 2 cm should be processed with one block per centimetre of their greatest dimension. In cases of (radical) trachelectomy/hysterectomy, the distal vaginal resection margin and all parametrial tissue should be processed completely. Sentinel lymph nodes have to be processed completely by lamellation along its long axis in 0.2 cm intervals. Immunohistochemical ultrastaging is mandatory. Staging should be performed using the 2009 FIGO classification and 2017 TNM classification. Reporting the revised 2018 FIGO classification is optional. To date, molecular markers have not been relevant for prognostication and treatment decision making.

Squamous and Glandular Epithelial Tumors of the Cervix: A Pragmatical Review Emphasizing Emerging Issues in Classification, Diagnosis, and Staging

Squamous cell carcinoma is the most frequent epithelial malignant tumor of the cervix and among the most frequent neoplasm in women worldwide. Endocervical adenocarcinoma is the second most common malignancy. Both tumors and their precursors are currently classified based on human papillomavirus status, with prognostic and predictive value. Various prognostic biomarkers and alternative morphologic parameters have been recently described and could be used in the management of these patients. This pragmatical review highlights recent developments, emerging issues as well as controversial areas regarding the cause-based classification, diagnosis, staging, and prognostic parameters of epithelial malignant tumors of the cervix.

Papillary Renal Cell Carcinomas Demonstrating Micropapillary Features: An Investigation Into the Diagnostic and Prognostic Implications

Aims: Papillary renal cell carcinoma (PRCC) with micropapillary carcinoma (MC) has been rarely described. We conducted a retrospective descriptive evaluation of the association of MC with PRCC and the possible prognostic implications.

Methods: A database search was made at the University of Southern California (USC) and Lenox Hill Hospital (LHH; New York City) in June 2016-June 2019 of PRCC cases with MC. Diagnosis of MC was made using routine histology, based on the presence of small clusters of cells without a vascular core. Features evaluated included: percent of MC, gross appearance, PRCC typing, nuclear grade, lymphovascular invasion, and lymph node metastasis.

Results: 848 RCC cases (690 from USC and 157 from LHH); 70 cases PRCC (54 from USC, 16 from LHH) of these cases, 13 had an MC, 12 were from radical nephrectomy, and 12 cases were male. Mean age was 68.3 years; seven were located in the right kidney. Average tumor size was 8.6 cm. MC ranged from 10% to 80% (average 37.5%), nine cases were PRCC type 2 and four type 1. Nuclear grade: three cases (grade 2), nine cases (grade 3), and one case (grade 4); 11 out of 13 tumors presented with extrarenal extension; nine cases that had lymph nodes submitted had metastatic carcinoma.

Conclusions: The presence of a micropapillary component in PRCC was found to be 18.5%, and it was predominantly associated with high pathologic stage and lymph node metastases. The clinical course of these tumors seems similar to MC in other tissues/organ systems. We advocate reporting this pattern when identified.

Key changes to the world health organisation (who) classification of female genital tumours introduced in the 5TH edition (2020)

An updated World Health Organisation (WHO) Classification of Female Genital Tumours was published in Autumn 2020. We discuss the major new additions and changes from the prior 2014 Classification with discussion of the reasons underlying these. A feature of the new Classification is the greater emphasis on key molecular events with integration of morphological and-molecular features. Most of the major changes from the prior Classification pertain to uterine (corpus and cervix) and vulval tumours but changes in all organs are covered.

[Pathological and Molecular Features of Lung Micropapillary Adenocarcinoma]

肺微乳头腺癌作为高级别肺腺癌，具频发转移、淋巴结浸润、复发率高和总体生存率低的临床特征。该亚型肿瘤中存在特征致癌因子通路的激活和肿瘤免疫微环境的建立。本文拟对近年来微乳头腺癌的病理学表现及分子学特征研究进展作一综述，旨在加深对微乳头型病变的认识，进而为制定特异性治疗策略奠定基础。

Tumor Typing of Endocervical Adenocarcinoma: Contemporary Review and Recommendations From the International Society of Gynecological Pathologists

The incidence of endocervical adenocarcinoma, the second most common cervical cancer in the world, has been on the rise. While most cervical cancers are squamous cell carcinomas and associated with high-risk oncogenic human papillomavirus (HPV), approximately 15% of endocervical adenocarcinomas, which now represent about one quarter of all cervical cancers, are HPV-independent. In this review, we will focus on the shortcomings of historical histologic classification systems of female genital tract tumors as they pertain to endocervical adenocarcinomas, and we will highlight the advantages of the new International Endocervical Adenocarcinoma Criteria and Classification system, which forms the basis for the WHO 2020 classification. We will cover the various histologic types, subtypes, and variants of endocervical adenocarcinoma with regard to morphology, immunophenotype, molecular genetics, HPV status and differential diagnosis, and we will provide International Society of Gynecological Pathologists recommendations for diagnosing these tumors.

Grading of Endocervical Adenocarcinomas: Review of the Literature and Recommendations From the International Society of Gynecological Pathologists

There is a lack of consensus regarding the prognostic value of grading endocervical adenocarcinomas and currently, no universally applied, validated system for grading exists. Several grading schemes have been proposed, most incorporating an evaluation of tumor architecture and nuclear morphology and these are often based on the International Federation of Gynecology and Obstetrics (FIGO) system for endometrial endometrioid carcinoma, although some schemes modify the proportion of solid tumor required to separate grades 1 and 2 from 5% to 10%. In the absence of a validated system, we endorse this approach for most human papillomavirus-associated endocervical adenocarcinomas and, based on the available evidence, recommend that tumors with ≤10% solid growth be designated grade 1, 11% to 50% solid growth grade 2 and >50% solid growth grade 3. Tumors should be upgraded in the presence of marked nuclear atypia involving the majority (>50%) of the tumor. Grading is not recommended for human papillomavirus-independent adenocarcinomas, since no validated system has been suggested and most of these neoplasms exhibit intrinsically aggressive behavior regardless of their morphologic appearance. Importantly, grading should not be performed for gastric-type adenocarcinomas, particularly as these tumors may appear deceptively "low-grade" yet still exhibit aggressive behavior. Recently devised, validated and reproducible etiology and pattern-based tumor classification systems for endocervical adenocarcinomas appear to offer more effective risk stratification than tumor grading and, in the future, these systems may render the provision of a tumor grade redundant.

The Silva Pattern-based Classification for HPV-associated Invasive Endocervical Adenocarcinoma and the Distinction Between In Situ and Invasive Adenocarcinoma: Relevant Issues and Recommendations From the International Society of Gynecological Pathologists

The Silva pattern-based classification for human papilloma virus-associated invasive adenocarcinoma has emerged as a reliable system to predict risk of lymph node metastasis and recurrences. Although not a part of any staging system yet, it has been incorporated in synoptic reports as established by the College of American Pathologists (CAP) and the International Collaboration on Cancer Reporting (ICCR). Moreover, the current National Comprehensive Cancer Network (NCCN) guidelines include this classification as an "emergent concept." In order to facilitate the understating and application of this new classification by all pathologists, the ISGyP Endocervical Adenocarcinoma Project Working Group presents herein all the current evidence on the Silva classification and aims to provide recommendations for its implementation in practice, including interpretation, reporting, and application to biopsy and resection specimens. In addition, this article addresses the distinction of human papilloma virus-associated adenocarcinoma in situ and gastric type adenocarcinoma in situ from their invasive counterparts.

Tumor Staging of Endocervical Adenocarcinoma: Recommendations From the International Society of Gynecological Pathologists

The International Federation of Gynecology and Obstetrics (FIGO) updated its staging system for cervical cancer in 2018 with changes that affect size criteria for early stage disease, as well as including pathology and radiology in addition to clinical assessment to be used in staging. Lymph node involvement was also included in the staging system. In early stage disease, pathologic findings are crucial in determining stage, which in turn determine treatment and prognosis for the patient. Therefore, it is imperative that there are unified and consistent methods and recommendations for assessing and reporting pathologic parameters for accurate staging. We describe the changes in the revised FIGO staging scheme and discuss controversial issues in cervical cancer staging from a pathologic perspective. We also provide practical recommendations regarding these parameters based on literature review and/or expert opinion/consensus.

Cervical carcinomas with serous-like papillary and micropapillary components: illustrating the heterogeneity of primary cervical carcinomas

Recent changes in the classification of cervical adenocarcinomas have re-categorized serous carcinoma as potentially nonexistent. However, clinical and pathological profiles of cervical adenocarcinomas with serous-like morphological features have not been systematically evaluated using the latest taxonomy and biomarkers. We studied 14 cases of primary cervical carcinomas with serous-like morphologies (papillary and micropapillary patterns). None of these cases exhibited evidence of serous carcinoma involving the upper tracts. Patient ages ranged between 34 and 86 years, most presented with abnormal uterine bleeding. Histologically, ten cases were classified as human papillomavirus (HPV)-associated carcinomas (eight usual-type endocervical adenocarcinomas and two adenosquamous carcinomas), of which six exhibited a papillary pattern and four had a micropapillary pattern. The four remaining cases were HPV-independent gastric-type adenocarcinomas, which displayed a papillary pattern in one case and a micropapillary pattern in three others. All ten HPV-associated carcinomas displayed block positive p16 and wild-type p53 by immunohistochemistry, with nine of them confirmed by HPV testing. Two of the four gastric-type adenocarcinomas had mutation-type p53, one of which also being p16 block positive. HER2 overexpression was demonstrated in 3/14 (21.4%) cases (2 HPV-associated and 1 HPV-independent). PD-L1 expression was identified in 4/10 (40%) cases, all HPV-associated. Targeted next-generation sequencing was performed in two cases with a micropapillary pattern, revealing a missense variant in ATM in an HPV-associated tumor and missense variants in TP53 and SMARCB1 in an HPV-independent tumor. The results demonstrated that primary endocervical adenocarcinomas can mimic the appearance of serous carcinoma, while not representing serous carcinoma. Serous-like papillary and micropapillary patterns may be present in both HPV-associated and HPV-independent cervical carcinomas, but none of the cases studied were unequivocally serous upon detailed analysis. Our findings support the exclusion of "cervical serous carcinoma" from existing classifications of cervical adenocarcinoma.

Invasive Micropapillary Carcinoma of the Uterine Cervix

We herein present a case of uterine cervical invasive micropapillary carcinoma (IMPC) in a 35-year-old woman. She had neither specific symptoms nor any previous gynecological history. A cervical punch biopsy revealed a high-grade squamous intraepithelial lesion and concurrent intestinal-type mucinous carcinoma. Based on the preoperative diagnosis of endocervical adenocarcinoma, she underwent radical hysterectomy with bilateral salpingo-oophorectomy and bilateral pelvic lymph node dissection. Grossly, there was an ovoid, slightly elevated mass with surface nodularity in the lower endocervix, measuring 10 × 8 mm. Histologically, the tumor consisted predominantly of tufts of tumor cells arranged in micropapillary structures devoid of fibrovascular cores and surrounded by clear, empty, lacunar spaces between tumor cell nests and stroma. The IMPC component comprised 90% of the entire tumor volume. The greatest dimension and stromal invasion depth of the IMPC were 8 and 3 mm, respectively (FIGO stage IA2). Immunostaining revealed that mucin 1 (MUC1) surrounded each micropapillary structure, indicating the reverse epithelial polarity of the glandular cells. MUC1 was localized predominantly in the stroma-facing surface of the cell clusters, accentuating the outlines of the micropapillary structures by forming a distinct, characteristic band on this surface. In addition, targeted sequencing analysis of the IMPC revealed a missense PIK3CA mutation (c.1633G>A). In summary, we present the clinicopathological characteristics of cervical IMPC. We demonstrate for the first time that IMPC of the uterine cervix harbors a pathogenic missense mutation in PIK3CA. Further investigations using larger cohorts of patients are necessary to confirm these findings.

Invasive Stratified Mucin-producing Carcinoma (ISMC) of the Cervix: A Study on Morphologic Diversity

Invasive stratified mucin-producing carcinoma (ISMC) is a recently described tumor with similar morphology to the stratified mucin-producing intraepithelial lesion. Stratified mucin-producing intraepithelial lesion and ISMC likely arise from human papillomavirus (HPV)-infected reserve cells in the cervical transformation zone that retain their pluripotential ability to differentiate into various architectural and cytologic patterns. This is important, as small studies have suggested that ISMC may be a morphologic pattern associated with more aggressive behavior than usual HPV-associated adenocarcinoma. We sought to study the morphologic spectrum of this entity and its associations with other, more conventional patterns of HPV-associated carcinomas. Full slide sets from 52 cases of ISMC were reviewed by an international panel of gynecologic pathologists and classified according to the new International Endocervical Criteria and Classification system. Tumors were categorized as ISMC if they demonstrated stromal invasion by solid nests of neoplastic cells with at least focal areas of mucin stratified throughout the entire thickness, as opposed to conventional tall columnar cells with luminal gland formation. Tumors comprising pure ISMC, and those mixed with other morphologic patterns, were included in the analysis. Twenty-nine pure ISMCs (56%) and 23 ISMCs mixed with other components (44%) were identified. Other components included 13 cases of usual-type adenocarcinoma, 6 adenosquamous carcinoma, 3 mucinous-type adenocarcinoma, 1 high-grade neuroendocrine carcinoma. ISMC displayed architectural diversity (insular, lumen-forming, solid, papillary, trabecular, micropapillary, single cells) and variable cytologic appearance (eosinophilic cytoplasm, cytoplasmic clearing, histiocytoid features, glassy cell-like features, signet ring-like features, bizarre nuclei, squamoid differentiation). Awareness of the spectrum of morphologies in ISMC is important for accurate and reproducible diagnosis so that future studies to determine the clinical significance of ISMC can be conducted.

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.

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.

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.