Paraneoplastic dermatomyositis related to a chondrosarcoma involving the cavernous sinus.

Approximately one third of all cases of dermatomyositis may be associated with malignancy. We describe a patient with unexplained rash, joint pain, and muscle weakness, who subsequently developed a cavernous sinus syndrome due to a central nervous system chondrosarcoma. Discovery of this tumor and further dermatologic evaluation, including skin biopsy, resulted in diagnosis of paraneoplastic dermatomyositis due to cavernous sinus chondrosarcoma.