Giant dermatofibroma. A little-known clinical variant of dermatofibroma.

Background : Dermatofibroma is a common cutaneous lesion that usually appears as a slow-growing firm dermal nodule. Objective : Our purpose was to report the clinical and histopathologic characteristics of eight giant dermatofibromas and review the few cases of this variant of dermatofibroma reported in the literature. Methods : All clinical records of two Departments of Dermatology of University Hospitals from the past 5 years with a diagnosis of dermatofibroma were reviewed. Lesions that measured 5 cm or larger were considered for this study. Biopsy specimens were available from all lesions. Results : Giant dermatofibromas are most frequently on the legs, especially below the knee. Often they have a pedunculated appearance. Because of their large size, the correct diagnosis is not suspected clinically; a diagnosis of malignancy is often made. Conclusion : Our findings indicate that giant dermatofibroma is a distinct but uncommon clinical variant of dermatofibroma that invariably exhibits a benign biologic behavior.