Nuchal-type fibroma in two related patients with Gardner's syndrome.

Nuchal-type fibroma is a distinct subcutaneous and dermal fibrous tissue proliferation that has been previously definitely identified in one patient with Gardner's syndrome and has been possibly present in two others. Gardner's syndrome is an autosomal-dominant condition with variable expressivity that comprises epidermoid cysts, fibrous tumors, osteomas, intestinal polyposis, as well as other findings. We report two cases of nuchal-type fibroma presenting in a 13-year-old boy in the right upper back and in his 60-year-old grandfather in the upper chest at the posterior axillary line. Both individuals carried a diagnosis of Gardner's syndrome and neither of them had diabetes. Although the boy has as of now only presented with cutaneous manifestations of Gardner's syndrome, his grandfather has exhibited both cutaneous and intestinal evidence of this syndrome. In addition, the boy's mother and her sister have documented Gardner's syndrome. Light microscopic findings of nuchal-type fibroma from both patients include paucicellular, haphazardly arranged collagen bundles with entrapped adipose tissue. A marked diminution of elastic fibers was noted with Van-Gieson stains. The lesions were diffusely positive for CD34 and contained a few factor XIIIa-positive cells. Electron microscopic analysis revealed no differences between the collagen comprising the nuchal-type fibroma as compared with control dermal collagen obtained from skin away from the tumor. These cases strengthen the view that there is an association between nuchal-type fibroma and Gardner's syndrome.