Image Description
Microscopic Features: Based on the microscopic appearance, three subtypes have been described: conventional fibroma, cellular fibroma, and mitotically active cellular fibrorma. Almost 90% of cases are conventional type.
The conventional ovarian fibromas are composed of uniform, bland spindle cells (resembling fibroblasts) arranged in short intersecting fascicles or in a storiform pattern (seen here). The cells have scant eosinophilic cytoplasm and oval or elongated wavy nuclei with minimal or no atypia. (continued in the next image)
About the Disease
Sex cord-stromal tumors of the ovary are a heterogenous group of relatively rare neoplasms arising from hormone-producing cells of ovarian cortical stroma. They make up approximately 8% of all ovarian tumors and are the most common ovarian tumors with endocrine manifestations. WHO Classification subdivides them into 3 main categories based on the predominant cell types. Pure stromal tumors have a mesenchymal appearance and include: fibroma, cellular fibroma, thecoma, luteinized thecoma with sclerosing peritonitis, sclerosing stromal tumor, microcystic stromal tumor, signet-ring stromal tumor, Leydig cell tumor, steroid cell tumor, and fibrosarcoma.Pure sex cord tumors have an epithelioid appearance and include: adult granulosa cell tumor, juvenile granulosa cell tumor, Sertoli cell tumor, and sex cord tumor with annular tubules.Mixed sex cord-stromal tumors include Sertoli-Leydig cell tumor, sex cord-stromal tumor, NOS, and gynandroblastoma.The most common are tumors in fibroma-thecoma group (80-85%) followed by granulosa cell tumors (10-15%). The remainder are quite rare. Most of the clinically malignant tumors are granulosa cell tumors. References:1. Mutter G. L.& Prat J (2014). Pathology of the Female Reproductive Tract - 3rd Edition. Churchill Livingstone Elsevier.2. WHO Classification of Tumors. Female Genital Tumors. 5th Edition, 2020; IARC, Lyon, France.3. Nucci MR, Parra-Herran C (2021). Gynecologic Pathology. 2nd Edition. Philadelphia, PA. Elsevier.4. Goldblum, J. R. et al (2018). Rosai and Ackerman's Surgical Pathology - Eleventh Edition. Philadelphia, PA. Elsevier.