[Paraneoplastic dermatomyositis revealing an undifferentiated nasopharyngeal carcinoma: about a case].

Dermatomyositis (DM) is an inflammatory disease of unknown origin that manifests as a myopathy associated with typical skin lesions. Association between DM and cancer is frequent (from 18% to 32% according to case series). It was described for the first time by Stertz in 1916 in association with gastric cancer. All histological types and sites of cancer in the general population may be associated with DM. Its association with nasopharyngeal carcinoma (NPC) is rarely described and the incidence proportion is 1 case of nasopharyngeal carcinoma per 1.000 persons.