(11) Hereditary osteoma cutis

Abstract

A family is presented in whom osteoma cutis occurred in three successive generations. The clinical, radiological and histological features and the other relevant investigations are discussed. The association between osteoma cutis and Albright's hereditary osteodystrophy (Albright et al. 1942) is discussed. Case reportsCase 1: A girl aged three years first developed hard nodules in the skin at the age of six months, since when they have increased in number and size. Coeliac disease was diagnosed at three years and has been controlled with moderate success by a gluten-free diet. She has also had occasional breath-holding attacks from the age of one year. She is otherwise healthy and normal in development and intelligence.On examination the patient had about eight 3-5 cm plaques in the skin, each plaque being composed of clusters of flat, hard, angulated, lentil-shaped nodules 0.5-1.5 cm diameter. The lesions were more easily palpated than seen; however, in some, the overlying skin was slightly discoloured with a dusky, violaceous hue ( Figure 1). Most of the lesions were situated on the trunk and thighs, but some had recently appeared on the extremities.Soft tissue X-rays of the abdomen confirmed the presence of subcutaneous calcified nodules and, in addition, X-rays of the hands and feet showed occasional specks of calcification around the metacarpals and metatarsals. X-rays of the long-bones and skull were normal. Other investigations including full blood count, urea and electrolytes, albumin, alkaline phosphatase, serum calcium, phosphate and parathormone assays, were all normal. Skin biopsies demonstrated the presence of multiple spicules of bone in the dermis (Figure 2). Normal membranous bone structure: osteocytes, cement lines and Haversian canals were present, together with occasional osteoblasts and osteoclasts. The surrounding dermis showed no evidence of scarring or inflammatory changes.