Pericardial hemangiosarcoma in a cat.

CASE SUMMARY: A 5-year-old, male castrated cat was presented with lethargy, tachypnea, and pleural and pericardial effusion. Echocardiographic assessment revealed an irregular hyperechoic structure that occupied a large portion of the thoracic cavity, expanding from the pericardium and surrounding the heart. Postmortem evaluation, histopathology and immunohistochemistry for factor VIII-related antigen confirmed the diagnosis of pericardial and splenic hemangiosarcoma.

RELEVANCE AND NOVEL INFORMATION: This case report highlights that hemangiosarcoma, despite being rarely reported, should be considered as a differential for pericardial neoplasms in cats.