Nonfamilial isolated collagenoma

Connective tissue nevi (CTN) are hamartomas consisting of the various components of the dermal connective tissue. The predominant element of the extracellular connective tissue within an individual nevus can be collagen, elastic fibers, or glycosaminoglycans. Those predominantly composed of collagen are called collagenomas. CTN can be classified as congenital or acquired, and independent or in association with a systemic disease. Collagenomas are asymptomatic and can be seen over the trunk, arm, thigh, and soles. We present the case of an 18-year-old boy with an isolated collagenoma over the lower back.