The strange association of Dermatomyositis-Polymyositis (DM-PM) and ca
ncer has been known for many years. We present the case of a 57-year-o
ld woman with polymyositis refractory to steroid therapy, in whom exte
nsive investigation finally revealed a squamous cell carcinoma of the
vagina. The clinical course of myositis paralleled the course of vagin
al cancer, with complete resolution of symptoms after radiotherapy for
the malignancy.