A Case of Eruptive Collagenoma on the Left Calf.

Eruptive collagenoma is an acquired connective tissue nevus without family history. It is typically described as numerous small papules or nodules on the trunk and arms with histopathological features of decreased or degenerated elastic fibers. We report a case of a 16-year-old male who presented with multiple asymptomatic 2 to 5 mm sized yellowish grouped papules on the left calf. Histopathologically, the lesion showed thickened homogenized collagen fibers highlighted by Masson trichrome stain and decreased and fragmented elastic fibers stained by Verhoeff-van Gieson stain. The skin lesion was diagnosed as eruptive collagenoma and no treatment was provided.