ACQUIRED CUTANEOUS OSTEOMATOSIS - A PRIMI TIVE MONOMELIC TYPE

Eight cases of sporadic acquired primary osteoma cutis have been repor ted in the literature. Age at onset varies from 16 to 55 years with a mean of about 35 years. The sex ratio is 1 and a wide range of localiz ations have been reported. There is no known treatment. We report a ne w case of primary osteoma cutis observed in an adult. The monomelic fe ature of this case has not been reported previously. The patient was 7 6 years old and had multiple painless, stone-like formations at severa l sites on the left thigh and leg since the age of 40. Histological ex amination of skin biopsies showed a perfectly differentiated bone tiss ue in the dermal layer. There was no similar family history nor abnorm al morphotype. Likewise, the absence of laboratory signs of pseudohypo parathyroidism, together with the late and spontaneous onset allowed u s to eliminate hereditary Albright's osteodystropy or secondary osteom atosis due to a local pathological process. Despite the late onset, th e monomelic character of the osteomas observed and the association of hemicorporeal hypertrophy and linear basocellular naevi reported in th e literature would suggest a hamartomatous origin rather than a metapl asic process in this patient.