Familial cutaneous collagenoma: genetic studies on a family*

Abstract

Familial cutaneous collagenoma is an inherited condition characterized by the presence of multiple dermal nodules symmetrically distributed on the trunk and upper arms. Six patients (the proband, his 4 siblings and a niece) representing a kindred of 52 subjects were examined for asymptomatic cutaneous nodules mainly on the back and chest. The individual lesions varied from a few millimeters to several centimeters in size, were indurated and showed minimal epidermal changes. Histologically, the nodules were characterized by an excessive accumulation of dense, coarse collagen fibers in the dermis. The elastic fibers appeared diminished in number, and in some areas were abnormally thin and fragmented. The lesions were connective tissue nevi of the collagen type. Based on family history and histological observations, the patients were diagnosed as having familial cutaneous collagenoma. Examination of the family pedigree indicated that the dermal nodules in familial cutaneous collagenoma were inherited in an autosomal dominant pattern. The lesions had an onset at the age of 15-19 yr, and their number increased significantly during pregnancy. Familial cutaneous collagenoma may be an inherited condition whose expression is under hormonal control.