Incomplete excision or postoperative hematoma: primary right ventricular intramyocardial lipoma involving the right ventricular outflow tract.

Primary benign cardiac tumors are relatively rare, and lipomas are even less frequent. We presented a case of primary intramyocardial lipoma involving the right ventricular outflow tract diagnosed through transthoracic echocardiography and surgical pathology. The tumor was completely resected. Surprisingly, an echogenic mass similar to the one seen before the operation in terms of the echogenicity and morphological characteristics was found at the same location 1 week after the complete resection. Was it an incomplete excision or a postoperative hematoma? After regular echocardiographic follow-up, the echogenic mass disappeared. It was inferred that the echogenic mass may have been a postoperative intramyocardial hematoma.