This case concerned a 67 old farmer who presented a vegetating and crusted tumor of the right knee. Histological examination revealed intracellular round structures PAS + within an inflammatory dermal granuloma, including epithelioid and giant cells. Alternaria could be isolated on cultures from biopsies of the tumor. Ultrastructural study specifies the morphological aspects of Alternaria within dermal granuloma; furthermore, large numerous myelinic bodies were present within the parasitic cells. The clinical aspect of the patient led to hormonal explorations and a Cushing's disease yet unrecognized was ascertained, that probably represented the "special terrain" which made the growth of Alternaria possible. The survey of the available literature revealed two cases of alternariosis and Cushing's syndrome, but in these two cases the diagnosis of the endocrinopathy was already established when the cutaneous infection developed. The lesion cleared within a month after electrocoagulation, local iodine compound and griseofulvine per os, with nonrelapse 12 months after.