[Pigmented nevus and cutaneous ossifications. Apropos of 125 cases of osteonevi]

In a series of 86,400 pathological examinations 125 cases of pigmented naevus associated with one or several foci of cutaneous ossification were observed. This association, known as osteonaevus of Nanta, account for 1.4 p. 100 of all pigmented naevi. In our series of examinations, osteonaevus was the most frequent cause (62 p. 100) of the 201 skin ossifications observed, the other causes being keratinizing basal cell epithelioma (7 p. 100) and pilomatricoma (5.5 p. 100). The patients' mean age was 46 years (range: 21-80 years), and 81 p. 100 of them were women. In almost every case the lesions were located on the head. The clinical diagnosis was always pigmented naevus, but it coexisted with inflammatory changes in 8 cases, and an underlying induration could be perceived at palpation in 4 cases. In 123 or ou 125 cases the pigmented naevus was restricted to the dermis, junctional theques being present in only 2 cases. The number of ossified foci varied from 1 in 45 p. 100 of the cases to 2 to 4 in 91 p. 100, and in 1 patient up to 8 foci were visible on the same section plane. The lesions presented as compact balls (135 cases), or lamellated bone (126 cases), or spicules of unorganized bone formations. They varied in size from 0.5 mm for balls to 1.5 mm for elements with a central cavity. In the latter were rudiments of bone marrow with capillary vessels, osteoclasts, adipose cells and cells that could be regarded as having haemopoietic functions. All naevi contained hair follicles.(ABSTRACT TRUNCATED AT 250 WORDS)