Perforating osteoma cutis: case report and literature review of patients with a solitary perforating osteoma cutis lesion.

Osteoma cutis, the development of bone in the dermis and/or subcutaneous fat, can occur as either a primary or secondary condition. Perforating osteoma cutis is rare. A man with a solitary lesion of perforating osteoma cutis is described and the features of individuals with a single perforating osteoma cutis skin lesion are reviewed. A solitary lesion of either primary or secondary perforating osteoma cutis has only been observed in two men and one woman; the lesions had been present from less than one month to 19 or 20 years prior to establishing the diagnosis. The lesion was either located on the forehead (two men) or the breast (one woman). The erythematous (two lesions) or flesh-colored nodules ranged in size from 8×8 millimeters to 1.5×0.5 centimeters. Each had epidermal perforation by bone through a central area that was either crateriform or crusted or keratotic. The clinical differential diagnosis included keratoacanthoma, phlebolith, pilomatricoma, pilomatrical carcinoma, and squamous cell carcinoma. The perforating osteoma cutis lesion was successfully treated with either excision or shave biopsy without recurrence at either 10 or 12-months follow-up.