Introduction/Background Uterine Carcinosarcoma (UCS) accounts 40 to 50% of all uterine sarcomas. It was known as a malignant mixed Mullerian tumor (MMMT) and recently has been categorized as high-grade endometrial cancer. UCS are aggressive tumors, presents with extrauterine disease in 60% of cases in initial presentation.

Methodology This is a case of a woman who presented with a pericardial effusion by neoplastic infiltration as a clinical manifestation.

Results A 60-year-old woman was admitted to the emergency room with dyspnea, chest pain, hypotension, distant heart sounds, elevated jugular venous pressure. Echocardiogram identified a pericardial collection and a drainage was performed, with an output of 268cc of bloody serous fluid. Liquid cytology was positive for neoplastic cells. Pericardial sampling revealed infiltration by adenocarcinoma. Immunohistochemical (IHC) suggested serous adenocarcinoma of uterine origin.

Patient with a history of postmenopausal bleeding 6 months ago. Magnetic Resonance Images (MRI) were obtained, which demonstrate a 12 × 9 cm heterogeneous intrauterine mass, with invasion of more than 50% of the myometrium, presence of bladder wall implants, multiples pelvic, paraortic and mediastinal lymph nodes. Endometrial sampling revealed high grade carcinoma and immunohistochemical conclusion was serous endometrial adenocarcinoma.

The woman was initially treated with six cycles of Paclitaxel and Carboplatin and during chemotherapy experienced moderate vaginal bleeding. She was submitted to five cycles of hemostatic radiotherapy (2000cGy). Subsequently, was performed total hysterectomy with bilateral salpingooforectomy. Final histopathological evaluation revealed endometrial carcinosarcoma with heterologous rhabdomyosarcomatous component with differentiation of peripheral nerve sheath. Eighteen months after the beginning of the systemic treatment (5 months after the surgery) she presents with peritoneal recurrence (ascites and intestinal subocclusion).

Conclusion UCS are relatively rare but very aggressive, treatment include surgery and combination with chemo and radiotherapy. Recurrence rates are high despite adequate treatment even in early stages. UCS accounts for all 15% of all deaths caused by uterine corpus malignancy.

Disclosure Nothing to disclose