Cutaneous meningioma underlying congenital localized hypertrichosis.

A 28-year-old man had a circumscribed hypertrichotic area on the left lumbar region since birth. A biopsy specimen showed numerous normal-appearing hair follicles and arrector pili muscles. In the subcutaneous layer a mass of dense collagenous connective tissue formed the background in which ill-defined foci of meningothelial cells in nests and pseudovascular spaces were seen. Collagenous structures (pseudopsammoma bodies), some of which showed calcification (psammoma bodies), were also seen. A diagnosis of cutaneous meningioma was made.