Endocardial location of familial myofibromatosis revealed by cerebral embolization: cardiac counterpart of the frequent intravascular growth of the disease?

Myofibromatosis is a rare infantile benign neoplasia, which may involve the heart in the rare and usually fatal generalized form of the disease. Diagnosis of endocardial myofibromas was made on two surgically excised lesions of the mitral valve that were reveled by a cerebral embolization in a 12-month-old female infant. Surprisingly, the patient had no other obvious lesion of myofibromatosis. However, her father had a histologically proven neonatal history of myofibromatosis. This case confirms the likely autosomal dominant mode of inheritance of myofibromatosis. It highlights the embolization risk of the previously unreported endocardial location. We suggest that these clinically isolated non-invasive endocardial myofibromas did not represent a true visceral form of myofibromatosis. They were, rather, similar to the frequent intravascular growth of the disease.