Beyond the ovary: Immunohistochemical evidence suggestive of upper gastrointestinal origin in a metastatic ovarian tumor – A diagnostic challenge

Metastasis to the female genital tract from extragenital neoplasms is uncommon but is associated with a significantly poorer prognosis. We report a case of a 41-year-old female with posthysterectomy status who presented with nonspecific gastrointestinal (GI) symptoms, including abdominal pain and distension. Routine laboratory investigations were within normal limits. Radiology (ultrasound and contrast-enhanced computed tomography) revealed a large ovarian mass with metastatic para-aortic lymph nodes, which was followed by a test for tumor markers, showing carcinoembryonic antigen elevation. Exploratory laparotomy showed a right-sided unilateral ovarian mass, and bilateral salpingo-oophorectomy, omentectomy, and bilateral pelvic lymph node dissection were performed. Histopathological analysis was suggestive of a primary ovarian tumor. However, on immunohistochemical examination of the tumor, immunohistochemical findings suggested a metastatic adenocarcinoma with features favoring an upper GI primary, thus underscoring the need for thorough histological and IHC assessment for accurate diagnosis and appropriate management. However, further radiological and endoscopic evaluation could not be completed due to loss to follow-up, limiting definitive confirmation of the primary site.