International journal of gynecological pathology : official journal of the International Society of Gynecological Pathologists

Endometrioid borderline tumors (EBTs) and seromucinous borderline tumors (SMBTs) are rare ovarian neoplasms with distinct histologic features. However, the molecular profiles of EBTs and SMBTs remain incompletely characterized. We performed…

Mesonephric-like adenocarcinoma (MLA) is a rare gynecologic malignancy primarily arising in the uterine corpus and ovaries. It shares remarkable similarities in its histomorphology, immunophenotype, and molecular features with mesonephric a…

Mesonephric-like adenocarcinoma (MLA) is a rare and aggressive gynecologic malignancy that has only been recognized in the last decade. It arises in the endometrium, ovaries, and other extrauterine sites (often in association with endometri…

Arteriovenous malformations (AVMs) are vascular anomalies defined by direct communications between arteries and veins with bypassing of the capillary network. Such lesions may be congenital or acquired. In the uterus, AVMs are considered un…

The simultaneous presence of distinct histologic types of ovarian cysts in a single patient, known as "collision tumors," presents a clinical challenge. In this study, we report 19 new cases of ovarian collision tumors involving both endome…

To evaluate whether deeper histologic sections and tissue-blocking practices improve the diagnosis of endometriosis in peritoneal biopsies. We retrospectively reviewed 148 peritoneal biopsy cases with clinical suspicion of endometriosis fro…

A well-differentiated endometrioid carcinoma at the site of extra-uterine/ovarian endometriosis complicates the differentiation between an uncommon metastatic pattern from a corpus cancer and a synchronous primary tumor originating from adj…

Ovarian clear cell carcinoma (OCCC) is an endometriosis-related neoplasm, in which traditional histologic grading does not show prognostic significance. Tumor budding was associated with poorer outcomes in OCCC in previous studies. We aimed…

Several types of myometrial invasion in endometrioid-type endometrial adenocarcinoma (EEC) have been identified: adenomyosis-like changes; adenoma malignum; broad front, single-cell/cell clusters; and the microcystic elongated and fragmente…

Definitive diagnosis of endometriosis is established by histologic confirmation in tissue from surgically visualized lesions; however, the diagnostic sensitivity of this approach varies widely. We hypothesized that incomplete tissue block s…

Research groups have identified 4 groups [polymerase epsilon (POLE) mutant, mismatch repair-deficient, p53-abnormal, and no specific molecular profile)] reflecting the Tumor Cancer Genomic Atlas Research Network subgroups in endometrial car…

Primary peritoneal cancer has characteristics similar to high-grade serous carcinomas of ovarian and fallopian tube origin. However, the relationship between endometriosis and primary peritoneal cancer is not well understood. This study foc…

Ovarian mesonephric-like adenocarcinoma (MLA) is a rare tumor with potential origins in endometriosis and Müllerian-type epithelial tumors. The morphologic patterns of MLA overlap with those of endometrioid ovarian carcinoma (EnOC). We spec…

The rectovaginal septum is an unusual location for neoplastic processes. The majority of these are extensions of tumors of the rectum or vagina. Masses arising primarily from the rectovaginal fascia are rare. Most primary rectovaginal malig…

Endometriosis is a common condition, with the ovary being the most common anatomic site. Endometriosis-particularly in the ovary-is associated with a risk of malignant progression, with a histologic spectrum of lesions from benign to malign…

Uterine mesenchymal lesions demonstrate various underlying genomic alterations involving MED12 , JAZF1 , YWHAE , BCOR , and ALK genes, among others. Recent publications describe a subset of high-grade endometrial stromal sarcoma lesions har…

Atypical endometriosis (A-EMS), defined by cytologic atypia and/or crowded glands resembling endometrial intraepithelial neoplasia, remains poorly understood. We aimed to refine the morphologic, immunohistochemical, and molecular features o…

Ovarian germ cell tumors (GCT) account for 2% to 3% of malignant ovarian neoplasms in Western countries and typically occur within the first 2 decades. When presenting later in life, GCTs may be associated with epithelial malignancies. In t…

Ovarian combined serous borderline tumor/low-grade serous carcinomas (SBT/LGSC) and mesonephric-like adenocarcinomas (MLA) have been previously reported and the presence of identical oncogenic somatic mutations in both components supports t…

Gynecologic carcinomas with RAS mutations may show a wide spectrum of histologic types, including mixed types. We present the case of a 63-yr-old patient diagnosed with an ovarian tumor harboring a mesonephric-like adenocarcinoma in a backg…

Mesonephric-like adenocarcinoma (MLA) of the ovary is a recently recognized, rare malignancy with aggressive clinical behavior, and is thought to originate from Mullerian epithelium with mesonephric transdifferentiation. Emerging evidence s…

Approximately 12% of routinely examined fallopian tubes of endometrial carcinoma (EC) cases have intraluminal tumor cells (ILTCs). ILTC associations with EC characteristics and outcomes are understudied, and unknown in serially examined and…

Nests of cells resembling urothelium, eponymously named "Walthard nests," are well-known incidental findings over the fallopian tube and occasionally undergo cystification resulting in clinical detection and surgical removal. Only rarely is…

Recent studies have provided molecular confirmation that a subset of yolk sac tumors is somatically derived. Somatically derived yolk sac tumors are typically diagnosed in older women and are often seen adjacent to epithelial proliferations…