Pedunculated lipofibroma. A clinicopathologic study of thirty-two cases supporting a simplified nomenclature.

Thirty-two cases are described of a relatively rare form of benign connective tissue proliferation characterized by ectopic fatty tissue in the dermis. The lesions usually appear as large, solitary, slow-growing, pedunculated to dome-shaped, skin-colored nodules or plaques showing predilection for the buttock and upper thigh. Other areas involved include the back, shoulder, knee, neck, and ear. Twenty patients were women and 12 were men, 19 to 78 years of age (mean, 46.9 years). The size of the lesions ranged from 4 to 69 mm (mean, 49 mm). Histologically, the lesions were characterized by the presence of mature adipose tissue infiltrating around the periadnexal adventitial dermis and between adnexal structures and admixing with dense stromal collagen. Marked deposition of mucopolysaccharides was noted in the majority of the lesions. Clinical follow-up in all 32 patients showed no evidence of recurrence. Because of their distinctive clinicopathologic features, we prefer to designate these lesions as solitary, pedunculated lipofibroma. In addition, seven of the patients had diabetes mellitus, suggesting a possible relation between the two conditions.