[Primary osteoma cutis].

Osteoma cutis is a rare tumour of the dermis which can only be diagnosed histologically. Pathogenetically, primary (neoplastic) and secondary (metaplastic) ossification must be differentiated. Primary ossification may lead to congenital osteomas and occurs in Albright's hereditary osteodystrophy and in Gardner's syndrome. Secondary, metaplastic ossification may be seen in association with cutaneous tumours, scars or inflammatory processes.