Microsporum canis mycetoma of the scalp.

Background. Mycetoma is a chronic subcutaneous tumefaction with presence of grains or granules. Etiological agents include bacteria or filamentous fun gi. Mycetoma due to dermatophytes is uncommon, mainly occurring in Africa. To our knowledge, no case has been reported in the West Indies. Only two ob servations of Micosporum canis mycetoma in humans have been reported in the literature. We report a third case of mycetoma of the the scalp caused by this fungus. Case report, A 22-year-old woman from Martinique, French West Indies, prese nted with an indolent tumefaction of the scalp evolving over five years. Sh e had mental retardation due to congenital adrenal hyperplasia with 21-hydr oxylase deficiency. The lesion was extracted surgically, Pathology and myco logy examinations showed features of Microsporum canis mycetoma. Two months later, the scalp lesion recurred and the patient was treated with griseofu lvin after surgical extraction. Discussion. Mycetoma due to dermatophytes is very uncommon, mainly observed on the scalp and nape of the neck. A history of a skin lesion is frequent, leading to transcutaneous penetration of the fungus and mycetoma formation . Several dermatophyte species have been identified as causal agents (Micro sporum ferrugineum, Trichophyton rubrum, Trichophyton verrucosum, Trichophy ton mentagrophytes, Microsporum audouinii, Microsporum langeronii). Microsp orum canis is rarely demonstrated in humans:two casts in children in Africa and Australia. Our observation was similar to the two cases in the literat ure: indolent and mobile tumefaction of the scalp, in a child or young adul t, suggestive of lipoma or epidermal cyst, with excision leading to diagnos is. Association with tinea capitis and skin or nail involvement can also be observed.