Concomitant intramyocardial and epicardial vasculitis in an autopsied heart allograft for cardiac rhabdomyosarcoma.

Primary cardiac tumours are rare, with only one quarter of the patients being malignant. The vast majority of malignant neoplasms of the heart are sarcomas. We describe a patient of primary cardiac rhabdomyosarcoma presented as coronary artery disease and recurrent myocardial infarction. Histopathologic finding of the excised native heart revealed a high grade pleomorphic rhabdomyosarcoma in the myoepicardial portion of the anterior wall with rupture. The accompanying unusual feature was myocardial infarction because of tumour emboli of the left anterior descending and left circumflex coronary arteries. After transplantation, the patient developed mild to moderate acute cellular rejection of the transplanted heart on post-transplantation day 1, 8, and 44, respectively. Unfortunately, he expired on the post-transplantation day 47 because of acute rejection, presenting as concomitant intramyocardial and epicardial lymphocytic vasculitis and multifocal myocardial ischaemia. We found that this uncommon medial lymphocytic vasculitis lesion was mediated by T cells and also by antibody directly against smooth muscle cells of small arteries. The consequence of such immune response would be compromised myocardial oxygenation resulting in allograft failure.