Nodular subepidermal fibrosis is a relatively common benign skin lesion. However, at Barnes Hospital (St. Louis) the correct diagnosis is made clinically in less than 30% of the excised lesions. Further, in nearly 10% of our cases, the clinical appearance prompted a diagnosis of some form of skin cancer. A clinicopathologic study of 610 lesions is presented to re-emphasize the existence of nodular subepidermal fibrosis, and its clinical and biological features.
The fact that four diagnostic synonyms are currently employed by pathologists reflects uncertainty regarding the etiology and histogenesis of nodular subepidermal fibrosis. The terms "dermatofibroma"1 and "sclerosing hemangioma"2 are at least as commonly applied as "nodular subepidermal fibrosis,"3 while "histiocytoma"4 is sometimes preferred. The nature of the lesion (neoplastic vs reactive-reparative) and the basic cell involved (histiocyte vs fibroblast vs endothelial) are debated. Whatever their origin, the biologic behavior of these small asymptomatic lesions is