Giant dermatofibroma with granular cell changes: side-effect of bee-venom acupuncture?

Dermatofibroma (DF) is a common benign fibrohistiocytic tumour with a predilection for the legs in middle-aged women. Giant DF, a rare clinical variant of DF, is characterized by its unusually large size. Granular cell change is typical of granular cell tumour, but can be observed in diverse cell lineages. Traumatic factors may be involved in the pathogenesis of giant DF and cellular granularity. We describe a 49-year-old Korean man with a giant DF showing granular cell differentiation, which may have been caused in part by multiple treatments with bee-venom acupuncture.