Advanced Uterine Carcinosarcoma With Fatal Suspected Pulmonary Embolism in a Resource-Limited Setting: A Rare Case Report.

Uterine carcinosarcoma (UCS), also known as malignant mixed Müllerian tumor (MMMT), is a biphasic neoplasm characterized by the presence of carcinomatous (epithelial) and sarcomatous (stromal tissue) elements. It frequently presents at an advanced stage and can mimic primary ovarian carcinoma on clinical and radiological evaluation, particularly when diagnosed after hysterectomy for presumed benign disease. To our knowledge, this represents one of the few reported cases of metastatic UCS from Sub-Saharan Africa. We report a case of advanced UCS in a 59-year-old postmenopausal woman who presented to a tertiary referral center in Northern Tanzania with a 6-month history of gradual-onset, progressive abdominal pain and distension. Physical examination revealed pallor, tachycardia, bilateral lower limb edema, and a large, irregular abdominopelvic mass. Contrast-enhanced CT scan demonstrated a massive heterogeneously enhancing abdominopelvic mass (24 × 22 × 12 cm) with central necrosis, diffuse peritoneal carcinomatosis, omental caking, and diaphragmatic deposits. Findings were also notable for hepatic surface scalloping, multiple liver lesions, bulky necrotic retroperitoneal lymphadenopathy, moderate ascites, and innumerable bilateral pulmonary nodules, suggestive of advanced ovarian malignancy with widespread metastases. Histopathological review of the archived hysterectomy specimen and an umbilical wedge biopsy revealed a biphasic tumor with atypical glandular (carcinomatous) and spindle cell (sarcomatous) components, including frequent mitoses and necrosis. Immunohistochemistry (IHC) showed cytokeratin positivity in tumor cells within the carcinomatous component and desmin positivity in the sarcomatous component. Based on clinicopathological correlation, the diagnosis was confirmed as UCS, FIGO stage IVB. A multidisciplinary tumor board recommended neoadjuvant carboplatin and paclitaxel chemotherapy followed by interval cytoreductive surgery. Before treatment initiation, she developed progressive bilateral lower limb swelling suggestive of deep vein thrombosis. Empirical anticoagulation with unfractionated heparin was started. However, she suddenly deteriorated after an assisted fall, with loss of consciousness and respiratory distress. The presumed cause of death was highly suggestive of massive pulmonary embolism, although confirmatory imaging or postmortem examination was not available secondary to cancer-associated venous thromboembolism (VTE), occurring in the setting of advanced stage IV uterine carcinosarcoma with extensive peritoneal, hepatic, and pulmonary metastases.