Pericardial Angiosarcoma: A Diagnostic Challenge.

Cardiac angiosarcomas are the most common malignant primary cardiac tumors accounting for 31% of all primary cardiac tumors. However, primary pericardial angiosarcomas are extremely rare and are associated with high mortality. A 41-year-old male with a past medical history of end-stage renal disease (ESRD) on hemodialysis, follicular thyroid carcinoma, hypertension, and asthma presented with recurrent pericardial effusions. Previously, different imaging modalities had shown small hemodynamically stable pericardial effusions with pericardial thickening. His pericardial effusion was attributed to his ESRD until this presentation. However, during the current admission, chest X-ray showed cardiomegaly with lobulated left heart border. Computed tomography (CT) and transthoracic echocardiogram showed an increased posterior complex pericardial effusion when compared to previous imaging. A pericardial window was created and the space was evacuated. Pericardial fluid cytology reported rare atypical cells, which were indeterminate for malignancy. Histopathology from the pericardial biopsy revealed fibrous tissue with cellular proliferation, consistent with an angiosarcoma. A positron emission tomography revealed findings of angiosarcoma (hypermetabolic pericardial soft tissue nodularity and complex pericardial fluid) limited only to the pericardium. Unfortunately, the angiosarcoma was deemed unresectable, and the patient underwent one cycle of chemotherapy with paclitaxel. The patient's hospital course was further complicated by myelosuppression from chemotherapy and disseminated intravascular coagulation. Therefore, no further chemotherapy was pursued. A repeat echocardiogram showed constriction of both ventricles with loculated pericardial effusion. The patient eventually transitioned to comfort care and passed away. Through this case report, we would like to highlight that multiple confounders can be present when considering the etiology of persistent pericardial effusions. We suggest contemplating alternate diagnosis, such as malignancy, and initiate aggressive work-up especially in young individuals with recurrent, unexplained pericarditis.