Familial cutaneous collagenoma

A 41-year-old woman presented to our dermatology clinic in February 2005 with a chief complaint of numerous flesh-colored nodules on her back and abdomen. She initially noticed the lesions at age 17 years. The plaques had increased in size and number over time, but remained asymptomatic. The patient reported multiple similar lesions on a maternal uncle and a cousin. Her family history was also notable for cardiomyopathy, resulting in the death of her mother. The patient's past medical history was notable for poorly controlled type I diabetes, currently managed with an insulin pump; and coronary artery disease. The patient had undergone multiple cardiac procedures before the age of 40 years, including quadruple coronary artery bypass grafting surgery and placement of 9 cardiac stents. Her ejection fraction on cardiac catheterization in November 2004 was 65% with no wall motion abnormalities. On physical examination, numerous spongy, discrete, flesh-colored plaques and nodules were seen concentrated across the upper part of her back between the scapulae as well as underneath the breasts and across the flanks (Figure 1). All lesions were asymptomatic. Prior workup of this patient had included plain films of the long bones and hands, which were within normal limits. A biopsy from lesional skin on the back highlighted by trichome stain showed an increased number of markedly thickened and eosinophilic dermal collagen bundles compared with adjacent normal skin. Immunohistochemical studies with anticollagen type I and type III antibodies confirmed that the increased collagen material consisted of type I collagen fibers, which is the same type of collagen found in normal dermis. The elastic fibers, highlighted by Verhoeff-van Gieson stain (Figure 2), were diminished and haphazardly arranged. No increased cellular component or inflammatory infiltrate was observed. These findings were consistent with a collagenoma. Further analysis of the lesional tissue by electron microscopy revealed that the ultrastructural appearance of the collagen fibers, including arrangement and diameters, were not significantly different from that of the normal tissue (Figure 3).