International Journal of Gynecological Pathology

TRPS1 is a novel immunohistochemical marker, so far quite specific and sensitive for breast cancer and especially useful for the diagnosis of triple-negative breast cancer. TRPS1 expression has recently been reported in normal skin appendages, as well as in a variety of benign and malignant cutaneous tumors, including adnexal tumors. However, it has not yet been reported in hidradenoma papilliferum (papillary hidradenoma), a benign adnexal neoplasm, accepted to originate from mammary-like glands in the vulvar or anogenital region of middle-aged women...

Low-grade serous carcinoma (LGSC) is an uncommon histotype of ovarian carcinoma, accounting for ~3% of cases. There is evidence that survival of peritoneal LGSC (pLGSC) is longer than that of ovarian LGSC (oLGSC). Key molecular alterations of LGSC have been established, including loss of CDKN2A and PR expression, MAPK pathway alterations, and loss of USP9X expression. We hypothesized that LGSC could be subclassified into clinically applicable molecular subtypes by a few surrogate tests similar to endometrioid carcinomas using a hierarchical decision tree based on the strength of the prognostic associations of the individual alterations...

Targeted anti-HER2 therapy has been recently added to the standard treatment recommendations in endometrial serous carcinoma. Current eligibility requires testing for HER2 overexpression and/or gene amplification by immunohistochemistry and by fluorescence in situ hybridization. However, clinical trials have also demonstrated the efficacy of anti-HER2 drugs against activating ERBB2/HER2 mutations in a variety of solid tumor types, and fam-trastuzumab deruxtecan is now approved by the US Food and Drug Administration for HER2-mutant non-small cell lung cancer...

The objective of this study was to analyze the expression and prognostic role of cancer-associated proteins in uterine leiomyosarcoma (uLMS). p53, DAXX, ATRX, HMGA2, IMP3, Stathmin, and phospho-Stathmin (p-Stathmin) protein expression by immunohistochemistry was analyzed in tissue microarrays from 244 uLMS. Expression was assessed for association with clinicopathologic parameters in 173 patients with available data. Tissue microarrays were informative in 230 cases. p53 was aberrant in 44% of tumors. DAXX, ATRX, HMGA2, IMP3, and Stathmin were expressed in 90%, 55%, 40%, 33%, and 97% uLMS, respectively...

Atypical polypoid adenomyoma (APA) is a polypoid biphasic lesion of low malignant potential that arises in the lower uterine segment and uterine corpus. The diagnosis of APA is often challenging on biopsy and curettage specimens, and both benign and malignant processes need to be considered in the differential. Stromal expression of p16 and SATB2 have recently been shown to distinguish APA from myoinvasive endometrioid carcinoma. The authors hypothesized that p16 and SATB2 immunohistochemistry could also aid in the distinction of APA from benign adenomyomatous polyp and endometrioid adenomyoma...

The molecular subtype classification of endometrial carcinomas has conceptually changed our approach to this disease. However, open questions remain about how to integrate certain histotype diagnoses with the molecular subtype. We report 2 cases with morphologic suspicion for endometrial carcinosarcoma, that still fell short of the essential criteria for diagnosing carcinosarcoma. On subsequent molecular testing pathogenic POLE mutations were detected and a descriptive diagnosis of endometrial endometrioid carcinomas, low-grade with a homologous sarcoma component was rendered...

Androgen receptor splicing variant 7 (AR-V7) is a truncated variant of the AR mRNA that may be a predictive biomarker for AR-targeted therapy. AR-V7 has been described in prostate, breast, salivary duct, and hepatocellular carcinomas as well as mammary and extra-mammary Paget disease. We report 2 gynecologic cancers occurring in the lower uterine segment and ovary and both harboring AR-V7 by targeted RNA sequencing. The uterine tumor was an undifferentiated carcinoma consisting of epithelioid cells and focally spindled cells arranged in sheets, nests, and cords associated with brisk mitotic activity and tumor necrosis...

The clinical imaging and pathology of a rare case of immature teratoma of the placenta is presented with a discussion of controversies related to classification and clinical suggestions for therapy and follow-up.

Endometrial and endocervical polyps not uncommonly exhibit focal benign "hobnail" change/metaplasia within the glandular epithelium, sometimes in association with inflammation or infarction. In most cases, this is readily recognized as benign but occasionally, especially in endometrial polyps, this change prompts consideration of a premalignant or malignant lesion, including early serous or clear cell carcinoma. Herein we highlight the previously unreported phenomenon of positive staining of this hobnail epithelium with Napsin A which has the potential to exacerbate concern for clear cell carcinoma...

Mucinous ovarian carcinoma is an uncommon malignancy characterized by resistance to chemotherapy and poor survival in the metastatic setting. HER2 amplification is a frequent late event in carcinogenesis, yet the incidence of HER2-low in mucinous ovarian carcinoma is unknown. Further, the optimal method for determining overexpression in these tumors is not established. We sought to assess the ASCO/CAP and ToGA trial scoring methods for HER2 IHC with correlation to FISH, p53, and mismatch repair protein status and to determine the incidence of HER2-low in mucinous ovarian carcinoma...

Carcinosarcoma (CS) is an aggressive form of gynecologic malignancy that accounts for ~5% of carcinomas in the endometrium and ovaries. There has been no significant improvement in survival over the last decades despite additional treatment options. PReferentially Expressed Antigen in MElanoma (PRAME) is an immunotherapy target used for the treatment of several solid tumors. We explored the PRAME protein expression levels in ovarian and uterine CS (n = 29). The expression levels were recorded by H-score (percentage of positively stained cells multiplied by staining intensity) in carcinomatous and sarcomatous components separately and compared by paired t-test...

We compared grading systems and examined associations with tumor stroma and survival in patients with cervical squamous cell carcinoma. Available tumor slides were collected from 10 international institutions. Broders tumor grade, Jesinghaus grade (informed by the pattern of tumor invasion), Silva pattern, and tumor stroma were retrospectively analyzed; associations with overall survival (OS), progression-free survival (PFS), and presence of lymph node metastases were examined. Binary grading systems incorporating tumor stromal changes into Broders and Jesinghaus grading systems were developed...

Mesonephric-like adenocarcinoma (MLA) has recently been described as a tumor of the endometrium or ovaries, which, morphologically and immunohistochemically, resembles mesonephric adenocarcinoma arising mostly in the uterine cervix. Herein, we report, to our knowledge, the first case of ovarian MLA that developed into an extremely rapidly growing recurrent mesonephric-like carcinosarcoma, as confirmed by a genomic profiling test. A 51-year-old woman underwent chemotherapy with complete debulking surgery for ovarian carcinoma...

A small subset of endometrial endometrioid adenocarcinoma cases first reported in 2003, showed a distinct cervical component with a so-called "burrowing" invasion pattern. Initially, the cervical component was regarded as cervical involvement by the endometrial adenocarcinoma. However, a 2010 study argued that these cases actually might represent separate primary endometrial and cervical endometrioid adenocarcinomas. However, additional data on this topic are scarce. Here, we report a case of endometrioid adenocarcinoma with a "burrowing" cervical invasion that is morphologically distinct from the patient's endometrial endometrioid adenocarcinoma...

Divergent differentiation in gynecologic carcinomas encompasses a broad range of lineages, including mesenchymal, germ cell, high-grade neuroendocrine, neuroectodermal, and cutaneous adnexal differentiation. Here we present a case of ovarian endometrioid adenocarcinoma with divergent malignant melanocytic differentiation (MMeD). The background ovarian endometrioid adenocarcinoma showed focally aberrant β-catenin expression and histologic patterns associated with β-catenin activation, including spindled elements and corded and hyalinized foci...

The studies on the molecular classification of endometrioid carcinoma (EC) with microcystic, elongated, and fragmented (MELF) pattern invasion are limited. In this study, 77 cases of ECs with MELF patterns in Chinese women were collected. The molecular classification of the fifth edition of the World Health Organization was used to classify the molecular subtypes using immunohistochemistry staining (mismatch repair [MMR]-immunohistochemistry: MSH2, MSH6, MLH1, and PMS2; p53) and Sanger sequencing targeted POLE ...

Immunohistochemical markers shown to be useful in identifying/confirming mesonephric/mesonephric-like differentiation (MLD markers) include thyroid transcription factor (TTF1), GATA-binding protein 3 (GATA3), and cluster of differentiation 10 (CD10). Only a few studies have examined the expression levels of MLD markers in endometrial endometrioid carcinomas (EECs). This study aimed to analyze the frequency and pattern of MLD marker expression in low-grade EECs. We performed immunostaining for the detection of TTF1, GATA3, and CD10 expression in 50 low-grade EEC tissue samples and evaluated their staining proportion and intensity...

At present, the prevailing concept is that high-grade serous carcinoma (HGSC) arises from the fallopian tubes (FTs). We report an HGSC case occurring in a serous ovarian cyst against the background of a serous tubal intraepithelial carcinoma (STIC)-like lesion. We also provide a literature review that contains references to clinical cases of the occurrence of STIC-like lesions in the ovary and phylogenetic studies that do not always reveal obvious bonds between early dysplastic serous lesions and HGSC. The article discusses cases of association between HGSCs of serous borderline tumors (SBTs) and low-grade serous carcinomas (LGSCs) in the context of their possible histogenetic relationship...

Human papillomavirus (HPV)-associated multiphenotypic sinonasal carcinoma is a rare and recently described epithelial neoplasm exhibiting myoepithelial differentiation and morphological overlap with salivary gland neoplasms, especially adenoid cystic carcinoma; it is commonly associated with HPV, especially type 33. It has mainly been reported in the nasal cavity and paranasal sinuses with a single case reported in the breast. Herein, we report the first vulval example in a 47-year-old patient who presented with a large craggy mass in the region of the Bartholin gland...

Erythrasma is a prevalent superficial bacterial infection typically caused by Corynebacteria species and preferentially affecting intertriginous sites including axillary, interdigital, and inguinal skin folds. However, erythrasma of the vulva is uncommon, with only 2 cases previously reported. Although erythrasma can be diagnosed clinically using Woods lamp examination, it may not always be considered in the differential diagnosis for patients presenting with persistent vulvar pruritus. We report 12 cases of vulvar erythrasma identified by histopathology, with a review of clinical and histologic features...