This is a histopathology image (hematoxylin and eosin stained) of an ovarian mass demonstrating a well-differentiated endometrioid carcinoma. The tumor displays tightly packed, back-to-back glands with minimal stroma, lined by neat, pseudostratified columnar epithelium. Nuclei are relatively uniform, with mild to moderate hyperchromasia and rare mitotic figures, consistent with low-grade morphology. The glandular lumina are often crescentic or slit-like; there may be cribriform arrangements in places. Surrounding ovarian stroma shows focal desmoplastic reaction and focal infiltration, supporting invasion by malignant epithelial cells. The tumor shows a predominantly tubular architecture resembling endometrial glands; mucin production is limited. Overall, the morphology fits endometrioid carcinoma of ovarian origin, grade 1. Differential considerations include mucinous or serous type ovarian carcinomas, metastatic endometrial adenocarcinoma, and clear cell carcinoma; however, the glandular pattern, cytologic uniformity, and absence of significant hobnail cells or prominent papillary features favor endometrioid histology. Clinically significant because endometrioid ovarian carcinomas are often associated with endometriosis and may present at an early stage; they may be estrogen-responsive; immunohistochemistry can show PAX8 positivity and variable ER/PR expression. This image is useful for educational teaching, histopathology differential diagnosis, and radiologic-pathologic correlation. Correlation with clinical staging and management is recommended.

Imaging modality: Histopathology, prepared as a hematoxylin and eosin stained section of uterine endometrium. The slide demonstrates papillary clusters of malignant epithelial cells forming intricate papillary fronds with fibrovascular cores. Cells show high-grade nuclear atypia, marked pleomorphism, conspicuous nucleoli, and brisk mitotic activity with frequent mitotic figures. Necrosis is evident in several regions. Psammoma bodies are present as concentric calcified cores within papillary structures. Notably, there is invasion into the myometrium, indicating an infiltrative growth pattern and depth of invasion that carries prognostic and staging implications (FIGO staging for endometrial carcinoma). The architecture is complex and papillary, rather than glandular, favoring serous-type histology; psammoma bodies and high-grade features strongly support serous endometrial carcinoma over endometrioid types. Inflammatory cells and stromal desmoplasia may be variably present. This histology correlates with aggressive behavior, propensity for lymphovascular invasion, and higher likelihood of extra-uterine spread. Clinically, this morphology aligns with postmenopausal bleeding in many cases and requires staging workup, including surgical intervention with lymph node assessment and consideration of adjuvant therapy (carboplatin/paclitaxel +/- radiation). Differential considerations include clear cell carcinoma and metastatic ovarian serous carcinoma to the endometrium. Accurate pathologic subtyping is critical for prognosis and treatment planning. This description enhances searchability and education.

This is a histopathology image (Hematoxylin and Eosin stained) of an ovarian tumor. The specimen is ovarian parenchyma with gland-forming epithelium showing a villoglandular pattern characteristic of endometrioid carcinoma. The glands are lined by stratified columnar epithelium with pale to dark nuclear chromatin, mild to moderate nuclear atypia, and apical cytoplasmic clearing in an overall well-differentiated architecture. The glandular spaces vary in size, with some back-to-back arrangements and occasional cribriform/ villous projections; stromal invasion is suggested by irregular gland termination into surrounding stroma. The histology resembles endometrium (hence endometrioid type) and the tumor constitutes approximately 10-25% of primary ovarian carcinomas, consistent with literature. The differential includes serous, mucinous, clear cell, and metastatic endometrial carcinoma to the ovary; immunohistochemistry and clinical correlation aid in distinguishing these entities. Diagnostic significance: recognition of ovarian endometrioid histology has implications for prognosis and treatment and warrants evaluation for synchronous endometrial pathology. This image is suitable for educational purposes, pathology review, and research on ovarian epithelial tumors, particularly for pattern recognition of villoglandular growth and stratified epithelium. Potential clinical use: differential diagnosis of ovarian neoplasms, surgical planning, grading, and correlation with patient management. Color and morphology of the glands may correlate with imaging features and tumor markers (e.g., CA-125) in clinical practice.

Imaging modality: bright-field light microscopy of a hematoxylin and eosin (H&E) stained endometrial tissue section from a biopsy. The tissue demonstrates nonatypical endometrial hyperplasia with crowding and architectural complexity of glands. The glands are lined predominantly by ciliated columnar epithelial cells with eosinophilic cytoplasm, showing typical tubal-type epithelium within the endometrium. Interspersed among the ciliated cells are round, clear cells consistent with tubal metaplasia. The stromal background is preserved, with no conspicuous cellular atypia or high-grade mitotic activity. The glands exhibit variable diameter and branching, yet maintain orderly polarity without cribriform destruction. Overall histology indicates benign metaplastic transformation rather than malignant invasion, and there is no definite cytologic atypia to suggest endometrial intraepithelial neoplasia or carcinoma. Recognizing tubal metaplasia in this setting is critical to avoid misinterpretation as serous or endometrioid carcinoma and to distinguish it from reactive or hormonal changes. Clinically, the finding may reflect underlying hormonal influences or sampling artifact; management decisions should integrate morphology with patient age and risk factors. This description supports educational use, differential diagnostic discussions, and research on endometrial metaplasia patterns in hyperplastic endometrium. The image thereby serves as a teaching exemplar for distinguishing benign tubal metaplasia from malignant glandular processes in endometrial pathology.