Primary cardiac angiosarcoma mimicking minoxidil-related pericarditis: a case report.

Background: Cardiac angiosarcoma, a rare and highly malignant primary cardiac tumour with poor prognosis, often presents diagnostic challenges owing to nonspecific clinical manifestations, with some cases initially presenting with acute pericarditis. Minoxidil, a commonly used treatment for androgenetic alopecia (AGA), has been associated with drug-induced pericarditis. Case summary: A 23-year-old man with no significant medical history presented with chest pain at rest and pericardial effusion. The patient had been taking 5 mg/day of oral minoxidil for AGA; thus, drug-induced pericarditis was initially suspected. His symptoms improved with aspirin and colchicine. However, he experienced recurrent episodes of pericarditis. On the third presentation, echocardiography revealed cardiac tamponade, and pericardiocentesis showed haemorrhagic pericardial effusion with elevated tumour markers. Imaging studies supported the suspicion of a primary cardiac malignancy. Surgical biopsy confirmed the diagnosis of cardiac angiosarcoma. The patient underwent extensive tumour resection followed by adjuvant chemotherapy and proton beam therapy and was discharged without evidence of recurrence. However, metastatic recurrence subsequently developed, and he died 30 months after surgery. Discussion: This case highlights the importance of considering malignancy in the differential diagnosis of recurrent pericarditis in young adults. Although minoxidil-related pericarditis was initially suspected, multimodal imaging and histopathological evaluation led to the diagnosis of cardiac angiosarcoma. Early identification and multidisciplinary management are essential in such rare presentations to improve patient outcomes.