Subareolar muscular hamartoma of the breast.

Hamartomas of the breast are rare lesions that may grossly simulate carcinomas: up till now fibrous, adipose and glandular tissues have been recognized within them. Here we report and discuss a case with the typical features of hamartomas, but displaying a marked smooth muscle component. The structure and localization of this tumour, and that of the few similar lesions reported in the literature, suggest that this peculiar type of hamartoma originates in the subareolar tissue.