Gardner's syndrome with epidermoid cysts showing features of pilomatrixomas

Summary Two brothers are described who were affected with Gardner's syndrome. Both had epidermoid cysts scattered over their irunk and limbs. Three of four epidermoid cysts removed from one of them and examined histologically showed an unusual change in which part of the wall of each cyst was replaced by granulation tissue and contained groups of shadow cells. Histo‐logical and histochemical studies established that these were epidermoid cysts and not pilomatrixomas. Gardner's syndrome is a genetically determined disorder in which multiple adenomatous polyps of the colon and rectum are associated with soft and hard tissue tumours (Gardner, 1951). Epidermoid cysts are the soft tissue tumours that occur mosl commonly in this syndrome, but on two occasions a calcifying epiihelioma of Malherbe (pilomatrixoma) has been reported (Piffaretti & Foroglou, 1965; Braillon, Chapuis & Boulanger, 1972). In the family described in this paper, the proband had three soft tissue tumours on his legs which histologically showed some features suggestive of pilomatrixomas. However, each was a typical epidermoid cyst in which part of the wall was replaced by granulation lissue and there were groups of shadow cells within the cyst. It is suggested that these lesions represent unusual epidermoid cysts rather than pilomatrixomas.