Unilateral athelia with a subcutaneous dermoid cyst.

A case of unilateral athelia with a subcutaneous dermoid cyst in the area in question is reported. The histologic features of the cyst wall suggest that it is derived from a base in the nipple-areola complex. Dozens of cases of congenital absence of the breast have been reported, some of them associated with congenital anhidrotic ectodermal dysplasia, others with additional musculoskeletal abnormalities, and still others normal in other respects. But to our knowledge, the combination of athelia and corresponding subcutaneous dermoid cyst has not been reported.