GATA3 Is a Sensitive and Specific Marker of Benign and Malignant Mesonephric Lesions in the Lower Female Genital Tract. Am J Surg Pathol. 2015;39:1411-1419. [PMID: 26135559 DOI: 10.1097/pas.0000000000000471]

Mesonephric Adenocarcinoma of the Uterine Corpus: Report of 2 Cases and Review of the Literature

Mesonephric adenocarcinoma (MNA) is believed to arise from benign mesonephric remnants or hyperplasia located in the lateral walls of the uterine cervix. They are uncommon in other sites of the gynecologic tract, and exceptionally rare in the uterine corpus. So far, only 30 cases of uterine MNA have been reported in the literature, as a result, the etiology, clinical behavior, choice of treatment, and histogenesis of uterine MNA are still unclear. In this study, we report 2 cases of MNA of uterine corpus. One case involved the inner half of myometrium with endometrial involvement; the second case involved the outer half of myometrium without endometrial involvement. We also reviewed the clinical and pathologic presentations of this rare entity, and discussed the histogenesis of uterine corpus MNA based on recent molecular findings.

Cytologic features of upper gynecologic tract adenocarcinomas exhibiting mesonephric-like differentiation

BACKGROUND

Mesonephric adenocarcinomas are rare neoplasms which most commonly arise in the lateral cervix and vagina. Tumors with similar morphologic, immunophenotypic, and molecular characteristics recently have been described in the uterine corpus and ovary. Herein, the authors sought to characterize the cytomorphologic features of adenocarcinomas exhibiting mesonephric-like differentiation arising in the upper gynecologic tract.

METHODS

Institutional databases were queried retrospectively for tumors of the upper gynecologic tract described as a "tumor of Wolffian origin" or "with mesonephric features" between 2007 and 2017. All available cytologic material was reviewed. Cytomorphologic characteristics were evaluated by 3 pathologists.

RESULTS

The current study cohort consisted of 8 cases taken from 7 patients. Primary sites included the ovary (3 cases); endometrium (4 cases); and pelvis, not otherwise specified (1 case). All cases demonstrated tight 3-dimensional clusters of overlapping cells. Additional architectural features included tubular (5 of 8 cases; 63%) and papillary (3 of 8 cases; 38%) formations. Cells were small with scant (7 of 8 cases; 88%) to moderate (1 of 8 cases; 12%) cytoplasm. Three of the 8 cases (38%) demonstrated extracellular hyaline globules. Nuclei were uniform in size (6 of 8 cases; 75%) or showed mild anisonucleosis (2 of 8 cases; 25%). Nuclear grooves and indentations were observed in all cases. Mitoses (5 of 8 cases; 63%) and apoptotic bodies (4 of 8 cases; 50%), when present, were rare. No necrosis was noted.

CONCLUSIONS

Adenocarcinomas exhibiting mesonephric-like differentiation show a monotonous population of small cells with scant to moderate cytoplasm and abundant nuclear grooves arranged in tight, overlapping, 3-dimensional clusters. Occasionally, papillary or tubular architecture, as well as extracellular hyaline globules, may be seen. These features should prompt further testing (eg, immunohistochemistry) to confirm the diagnosis and to exclude potential mimics.

Cervical Mesonephric Adenocarcinoma With Novel FGFR2 Mutation

Mesonephric adenocarcinoma is a rare tumor, accounting for <1% of cervical cancers. Well-differentiated mesonephric adenocarcinoma can be difficult to distinguish from diffuse mesonephric hyperplasia. Herein, we report a case of well-differentiated mesonephric adenocarcinoma with an FGFR2 mutation not previously reported in the literature. Nonselective tyrosine kinase inhibitors or FGFR2 inhibitors may represent options for targeted therapy.

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.

Mesonephric adenocarcinoma of the cervix: a case report with a three-year follow-up, lung metastases, and next-generation sequencing analysis

Background

Mesonephric adenocarcinoma (MNAC) is a rare tumor of the female genital tract, which originates from mesonephric duct remnants. Its diagnosis is pathologically challenging, because MNAC may exhibit a mixture of morphological patterns that complicates the differential diagnosis.

Case presentation

The patient in this case was a 48-year-old woman with a polypoid mass protruding into the endocervical canal. The patient underwent a total hysterectomy outside the institution. During biopsy, the mass showed a cerebroid aspect. Histological study revealed a tumor with a predominantly tubular and ductal growth pattern. The immunoprofile showed negative staining for calretinin, carcinoembryonic antigen (CEAm), estrogen receptors (ER), and progesterone receptors (PR), and positive staining for CD10, p16, and PAX2. The Ki-67 score was 46%. Using a next-generation sequencing assay, we documented genomic alterations in KRAS and CTNNB1, low tumor mutation burden (TMB), and an absence of microsatellite instability. In addition, gain of the long arm of chromosome 1 (1q) was also documented using chomogenic in situ hybridization (CISH). Three years later, the patient presented pulmonary nodules in the lingula and left basal lobe that were resected by thoracotomy. The histopathologic study of the pulmonary nodules confirmed the presence of metastases.

Conclusion

Carcinomas of mesonephric origin are among the rarest subtypes of cervical tumors. We report the first case of mesonephric adenocarcinoma of the cervix with lung metastases showing a CTNNB1 gene mutation.

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.

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.

International Endocervical Adenocarcinoma Criteria and Classification: Validation and Interobserver Reproducibility

The current World Health Organization (WHO) classification for endocervical adenocarcinoma (EA) is based on descriptive morphologic characteristics; however, it does not fully reflect our current knowledge of the diverse pathogenesis of cervical glandular neoplasia. A novel classification system, the International Endocervical Adenocarcinoma Criteria and Classification (IECC), which incorporates etiology and biological behavior into the morphologic scheme, has been recently proposed. We aimed to validate the IECC by assessing its interobserver reproducibility in comparison to the WHO system. A cohort of 75 EAs was reviewed independently by 7 gynecologic pathologists and categorized following IECC and WHO criteria based on hematoxylin and eosin material alone and after immunohistochemistry results for p16, PR, p53, Napsin-A, vimentin, CDX2, and GATA3 were provided. Human papillomavirus (HPV) in situ hybridization and polymerase chain reaction results were compared with consensus diagnoses. IECC was superior to WHO in terms of interobserver agreement with κ=0.46 versus 0.3, respectively, on hematoxylin and eosin review and κ=0.51 versus 0.33, respectively, with immunohistochemistry. Under the IECC, 73 (97%) of EAs had majority agreement (≥4 reviewers in agreement) whereas 42 (56%) had perfect agreement (7/7 reviewers in agreement). Conversely, WHO showed majority agreement in 56 (75%) and perfect agreement in only 7 (10%) EAs. Reproducibility was poor in HPV-related WHO types (usual κ=0.36, mucinous not otherwise specified κ=0.13, intestinal κ=0.31, villoglandular κ=0.21) and good in major HPV-unrelated categories (gastric type κ=0.63, clear cell κ=0.81, mesonephric κ=0.5). Classification as per the IECC had excellent correlation with HPV status (by RNA in situ hybridization or polymerase chain reaction). We have shown that the IECC has superior interobserver agreement compared with the WHO classification system, and that distinction between HPV-related and HPV-unrelated EA can be made with good reproducibility and excellent prediction of HPV status. WHO morphologic variants of HPV-related EA are poorly reproducible. Conversely, agreement is high among important high-risk HPV-unrelated subtypes. Thus, our results further support replacing the current WHO classification with the IECC.

Strong androgen receptor expression is not useful in distinguishing GATA3 + metastases

GATA binding protein 3 (GATA3) immunohistochemical expression is commonly considered to be a sensitive and specific diagnostic marker for breast and urothelial carcinomas in surgical pathology practice. However, since its expression has been also demonstrated in other tumors, GATA3 should be better used in conjunction with other immunohistochemical markers to establish tumor primitivity in metastatic setting. Interestingly, GATA3 expression seems to be significantly correlated with androgen receptor (AR) expression in breast carcinoma. In addition, strong AR expression -defined as immunohistochemical positivity in more than 60% of tumor cells- was suggested to be 100% specific for breast origin in GATA3+ metastases. The aim of this study was to verify whether strong AR expression may actually be useful to determine primivity in GATA3+ metastatic setting. Thus, we investigated AR and GATA3 immuno-expression in a cohort of metastatic tumors derived from urothelial, breast, endometrial and salivary gland carcinomas. We did not find any GATA3 or AR expression in the metastases from endometrial or salivary gland carcinomas, while GATA3 expression was seen in the majority of metastases from urothelial or breast carcinomas. In addition, strong AR expression was seen in 73% and in 47% of metastatic breast and urothelial carcinomas, respectively. On the whole, our findings confirm that GATA3 is sensitive and specific for breast and urothelial origin in metastatic setting. According to our results, strong AR expression is not useful to distinguish breast from urothelial primitivity, as previously suggested.

[Ectopic tissue of the female genital tract]

Ectopias of female genital tissues are a common event in routine pathology. Mostly they derive from paramesonephric tissues displaced during embryonal development or later. However, gonadal-, mesonephric-, or mesothelial-derived tissues may also appear in unusual localizations in and outside the female genital tract. They may be the source of benign and malignant tumors or tumor-like lesions. This review aims to provide an overview of possible tissue ectopias and to improve the developmental understanding of tumorous diseases of the female genital tract. Ectopias of primarily extragenital tissues in the female genital tract are also reviewed.

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.

Mixed Mesonephric Adenocarcinoma and High-grade Neuroendocrine Carcinoma of the Uterine Cervix: Case Description of a Previously Unreported Entity With Insights Into Its Molecular Pathogenesis

Human papillomavirus (HPV)-negative cervical carcinomas are uncommon and typically encompass unusual histologic subtypes. Mesonephric adenocarcinoma is one such subtype. Mesonephric tumors in the female genital tract are thought to arise from Wolffian remnants, and are extremely rare tumors with widely variable morphology. Sarcomatoid dedifferentiation has been previously described in a few cases, but other forms of dedifferentiation have not been reported. Neuroendocrine carcinoma of the cervix (e.g. small cell carcinoma) is associated with HPV infection, typically HPV 18. These tumors often arise in association with a conventional epithelial component such as squamous cell carcinoma or usual-type endocervical adenocarcinoma. We describe a case of mesonephric adenocarcinoma of the uterine cervix associated with an HPV-negative high-grade neuroendocrine carcinoma at the morphologic and immunophenotypic level, for which we performed targeted massively parallel sequencing analysis of the 2 elements. Both components shared identical mutations in U2AF1 p.R156H (c.467G>A) and GATA3 p.M422fs (c.1263dupG), as well as MYCN amplification. In addition, the neuroendocrine carcinoma harbored TP53 and MST1R mutations not present in the mesonephric carcinoma. Our data suggest a clonal origin of the 2 components of this rare entity, rather than a collision tumor.

Uterine Paramesonephric Cysts in Sprague-Dawley Rats from National Toxicology Program Studies

Congenital uterine wall cysts arising from paramesonephric (Müllerian) and mesonephric (Wolffian) ducts are typically incidental findings in most species. We used immunohistochemistry to characterize and determine the origin of uterine cysts in Sprague-Dawley (SD) rats from multigeneration studies conducted by the National Toxicology Program. Subserosal uterine cysts were observed in 20 of the 2,400 SD rats evaluated in five studies, and 10 cysts were characterized for this study. Single cysts were unilocular, fluid-filled, and occurred throughout the uterus. Microscopically, all cysts had a well-developed smooth muscle wall, lined by flattened to cuboidal, sometimes ciliated, epithelium that stained intensely positive for cytokeratin 18 and paired box protein 8 (PAX8). Most cyst epithelia displayed weak to moderate positivity for progesterone receptor (PR) and/or estrogen receptor α (ER-α), as well as were negative for GATA binding protein 3 (GATA3). Cyst lumens contained basophilic flocculent material. The cysts appeared to be developmental anomalies arising from paramesonephric tissue based on positive PAX8 and ER-α and/or PR staining. Additionally, 70% of the cysts lacked GATA3 expression. Taken together, the subserosal uterine cysts observed in adult rats in these studies most likely arose from the paramesonephric duct.

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.

Mesonephric proliferations of the female genital tract

The mesonephric (Wolffian) duct regresses in females during embryological development. Remnants of this duct may persist typically along the lateral walls of the cervix, vagina, adnexa, and uterine corpus. These mesonephric epithelia may expand into hyperplastic proliferations and rarely form neoplasms. The spectrum of morphology, immunophenotype, clinical presentation, and molecular characteristics of mesonephric lesions is reviewed, with attention to distinction from entities in the differential diagnosis.

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.

Mesonephric adenocarcinoma of the uterine corpus with intracystic growth completely confined to the myometrium: a case report and literature review

BACKGROUND

Mesonephric adenocarcinoma (MA) is a rare tumor believed to arise from mesonephric remnants occurring mostly in the uterine cervix and, to a lesser extent, the corpus. Since the first case report of MA in the corpus in 1995, only 16 cases have been reported in the English literature. A recent report suggested that MA originates in Müllerian tissue and exhibits the mesonephric differentiation phenotype.

CASE PRESENTATION

An asymptomatic 61-year-old woman was referred to our hospital because of elevated levels of tumor markers. Imaging revealed an intramural lesion of the uterine corpus exhibiting fluorodeoxyglucose uptake. A total hysterectomy and bilateral salpingo-oophorectomy were performed. The tumor was completely confined to the corpus wall and was composed of an intracystic bulky component and an invasive component in the myometrial layer. The tumor exhibited a variety of growth patterns, including a characteristic tubular pattern with dense eosinophilic secretion reminiscent of the thyroid, as well as a variety of morphologies, such as acinar, papillary, and ductal structures. The structures were immunoreactive for CK7, vimentin, CD10, calretinin, PAX8, and GATA3 and almost completely negative for ER/PgR. CA125 and CA19-9 antigen expression was also detected.

CONCLUSION

A case of MA with a unique growth pattern of an intracystic mass within the corpus wall is presented. The histogenesis and differential diagnoses are discussed. The histogenesis of MA is not yet clear. We hypothesize two different pathways involved: 1) direct development from the mesonephric remnants and/or 2) mesonephric transformation of Müllerian adenocarcinoma.

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.

Markers of metastatic carcinoma of breast origin

This review summarizes the three major breast-associated markers that can be of assistance in evaluating metastatic carcinomas for which a breast primary diagnosis is entertained. These markers include gross cystic disease fluid protein-15 (GCDFP-15), mammaglobin, and GATA3. The first two are cytoplasmic markers that show comparable sensitivities for breast cancer, although relatively few of the published studies have employed the same antibodies against the target molecule, making direct comparisons challenging. GATA3 is a nuclear transcription factor that shows superior sensitivity to GCDFP-15 and mammaglobin. However, the specificity of GATA3 can pose challenges, inasmuch as carcinomas of the bladder and other sites can show significant levels of positivity. Determination of the optimal panel of antibodies employed in a given clinical setting will thus depend on the non-breast tumours included in the differential diagnosis.

Mesonephric (Wolffian) Pseudoendometrioid Carcinoma of the Broad Ligament, Arising From a Papillary Cystadenoma

This article describes the case of a 70-year-old woman with an adnexal cystadenocarcinoma located in the right broad ligament and displaying a striking resemblance to a well-differentiated endometrioid adenocarcinoma. The uniqueness of this pseudoendometrioid carcinoma lies in the fact that its mesonephric nature is revealed by the origin from a papillary cystadenoma of the broad ligament, where remnants of the mesonephric duct are seated, and the immunohistochemical profile, particularly a uniform negativity for estrogen and progesterone receptors, apical-luminal positivity for CD10, and strong nuclear positivity for GATA3.

Hormone receptor-negative, thyroid transcription factor 1-positive uterine and ovarian adenocarcinomas: report of a series of mesonephric-like adenocarcinomas

AIMS

To report a series of uterine corpus (n = 7) and ovarian (n = 5) neoplasms which we believe probably represent mesonephric adenocarcinomas based on their characteristic morphology and immunophenotype.

METHODS AND RESULTS

All neoplasms exhibited a relatively constant and characteristic morphological appearance with an admixture of architectural patterns with small glands or tubules, some containing luminal eosinophilic colloid-like material, typically predominating. Solid and papillary architectures were also often present. The nuclear features were characteristic with atypical angulated clear vesicular nuclei which often exhibited overlapping. All the tumours were 'flat' negative with oestrogen receptor and progesterone receptor and all except one exhibited nuclear staining with thyroid transcription factor 1 (TTF1), which was often diffuse. All tumours exhibited wild-type staining with p53. CD10, calretinin and GATA binding protein 3 (GATA3) were positive in a variable proportion of the neoplasms.

CONCLUSIONS

We believe these neoplasms to represent mesonephric adenocarcinomas which have only rarely been reported to arise in the uterine corpus and never in the ovary. We recommend they be termed mesonephric-like adenocarcinomas until their histogenesis is firmly established.

Recent Developments in Non-HPV-related Adenocarcinomas of the Lower Female Genital Tract and Their Precursors

Most adenocarcinomas in the lower female genital tract (cervix, vagina, vulva) arise in the cervix and are associated with high-risk human papillomavirus (HPV) infection. However, there is an emerging spectrum of non-HPV-related cervical adenocarcinomas, the most common of which is so-called gastric type. In this review, the concept of gastric-type cervical adenocarcinomas and their possible precursor lesions is covered, the precursor lesions still being poorly understood. Other non-HPV-related cervical adenocarcinomas are also discussed, including new information regarding molecular events in mesonephric adenocarcinoma. A variety of primary vaginal adenocarcinomas, including clear cell, endometrioid, intestinal and gastric types are also discussed. The spectrum of benign and malignant glandular lesions involving the lower female genital tract and probably derived from misplaced Skene's (periurethral) glands is also covered.

Targeted genomic profiling reveals recurrent KRAS mutations and gain of chromosome 1q in mesonephric carcinomas of the female genital tract

Mesonephric carcinoma is a rare form of gynecologic cancer derived from mesonephric remnants usually located in the lateral wall of the uterine cervix. An analogous tumor occurs in the adnexa, female adnexal tumor of probable Wolffian origin. The pathogenesis and molecular events in mesonephric carcinoma are not known. The aim of this study was to examine the molecular alterations in mesonephric carcinoma to identify driver mutations and therapeutically targetable mutations. This study consisted of 19 tumors from 17 patients: 18 mesonephric carcinomas (15 primary tumors and three metastatic tumors) and 1 female adnexal tumor of probable Wolffian origin. In two patients, both primary and metastatic tumors were available. Genomic DNA was isolated and targeted next-generation sequencing was performed to detect mutations, copy number variations, and structural variants by surveying full exonic regions of 300 cancer genes and 113 selected intronic regions across 35 genes. Fluorescence in situ hybridization (FISH) for 1p and 1q was performed in two cases. Eighty-one percent (13/16) of mesonephric carcinomas had either a KRAS (n=12) or NRAS (n=1) mutation. Mutations in chromatin remodeling genes (ARID1A, ARID1B, or SMARCA4) were present in 62% of mesonephric carcinomas. All mesonephric carcinomas lacked mutations in PIK3CA and PTEN. The most common copy number alteration was 1q gain, found in 12 (75%) mesonephric carcinomas; this was confirmed by FISH in two cases. Mesonephric carcinoma is characterized by molecular alterations that differ from those of more common variants of cervical and endometrial adenocarcinoma, which harbor KRAS/NRAS mutations in 7% and 25% of cases, respectively. KRAS/NRAS mutations are common in mesonephric carcinoma and are often accompanied by gain of 1q and mutations in chromatin remodeling genes. Targeting inhibitors of the RAS/MAPK pathway may be useful in the treatment of mesonephric carcinoma.

Mesonephric Adenocarcinoma of the Uterine Corpus: A Case Report and Diagnostic Pitfall

Mesonephric adenocarcinoma is a rare tumor type that is usually found in areas where the Wolffian duct was present during the fetal period. We report a case of mesonephric adenocarcinoma of the uterine corpus in a 66-year-old woman who presented with vaginal bleeding. Pelvic magnetic resonance imaging revealed a 2.7-cm-sized irregular thickening and enhancement of the uterine body. The diagnosis following endometrial curettage biopsy was endometrioid adenocarcinoma, and the patient underwent a total hysterectomy with bilateral salpingo-oophorectomy. The tumor was composed of small tubular and ductal components, and a retiform appearance was also observed in the deeper areas. The tumor cells were immunopositive for cytokeratin, vimentin, CD10 with a luminal staining pattern, PAX2, and PAX8, and immunonegative for estrogen receptor and progesterone receptor, which was consistent with tumor of mesonephric origin. Mesonephric neoplasms reveal relatively low-grade nuclear feature, characteristic immunoprofiles (immunonegative for ER and PR, and immunopositive for CD10, PAX2, PAX8, and GATA3), and unique tumor location (myometrium), whereas Müllerian neoplasms such as endometrial adenocarcinoma show various morphology, immunopositivity for ER and PR, and primarily endometrial location. As described above, an integration of the clinical features, morphologic characteristics, and immunohistochemical profiles is needed to make a diagnosis.