Tumoral mycetoma of the buttock.

Background. Mycetomas are actinomycosic or fungal infections where the infe ctious agent produces grains. We report an atypical case of fungal mycetoma presenting as a tumoral formation on the buttock. Case report. A 56-year-old unemployed man from the Diourbel region of centr al Senegal consulted in February 1997 for a fistulalized tumor of the right buttock which had developed spontaneously and progressed for 5 years. The patient's general health remained satisfactory. Physical examination showed a voluminous 25 cm tumefaction extending from the right buttock to the per ineum. The tumor showed a few areas of fistualization which discharged blac k grains under pressure. There was a 1.5 cm right inguinal node which did n ot appear to be inflammatory. The remainder of the physical examination was normal. Pathology reported inflammatory connective tissue surrounding a br ownish polycyclic grain composed of spores and mycele filaments. The diagno sis of fungal mycetoma was retained and surgical excision under general ane sthesia was performed. Discussion. This is an atypical case of fungal mycetoma because of its tumo ral form and gluteal localization. The differential diagnosis was cutaneous neurofibroma, myoma, or Darier-Ferrand dermatofibrosarcoma. The frequency of extrapodal red grain mycetomas has been pointed out by several authors f rom Senegal, but extrapodal black grain forms as seen in our case are more exceptional.