Rare Presentation of Anaplastic Carcinoma as a Mural Nodule in Mucinous Cystadenoma with Concurrent Benign Brenner Tumor

Abstract Introduction/Objective Mural nodules in ovarian mucinous tumors, particularly which are anaplastic carcinomas, represent an exceedingly rare and complex diagnostic category. The literature documents only a few such tumors, predominantly sarcoma-like, with favorable prognoses. In contrast, malignant mural nodules, including anaplastic carcinoma and sarcomatous or carcinosarcomatous types, are notably rare, with fewer than ten cases reported. The co-occurrence of an anaplastic carcinoma mural nodule with a benign Brenner tumor presents distinct diagnostic and treatment complexities stemming from mixed tumor pathology and associated genetic mutations like KRAS and p53, critical in the development of these unusual nodules. This report deepens our insight into rare ovarian tumors. Methods/Case Report A 60-year-old woman with persistent lower abdominal pain underwent surgery for a suspected benign ovarian cyst based on initial imaging. The removed ovary contained a 10.5 x 10 x 8 cm unilocular cyst lined with benign, mucin-containing columnar epithelium. However, a 2 cm anaplastic carcinoma mural nodule was identified within the cyst, exhibiting cellular pleomorphism, nuclear atypia, and high mitotic activity. Immunohistochemical staining confirmed the carcinoma with diffuse cytokeratin and EMA positivity. The fallopian tube was free of tumor involvement, and no capsular or lymphovascular invasion was seen. The cancer was staged as PT1a, pNx, pMx. Results (if a Case Study enter NA) NA Conclusion Anaplastic carcinoma, when present as a mural nodule within a benign-looking mucinous cystadenoma, demands an aggressive treatment strategy due to its poor prognosis and aggressive nature. Such cases require a deviation from standard benign treatment protocols to include extensive surgery, possibly, depending on disease progression, chemotherapy or radiation.