Background: Focal myositis (FM) is an extremely rare, mainly self-limited disease, affecting mostly muscle of lower limb.
Case Report: We present a case of FM in 34-year-old with persistent course. The lesion appeared in patient’s right calf as painless tumor. The diagnosis of the FM was established on the base of clinical features and biopsy. The disorder occurred resistant to treatment with corticoids and metotrexate. After 7 months since the FM diagnosis weakness of the left calf muscles appeared that was connected with the vertebral canal tumor reveled by nuclear magnetic resonance. The patient successfully underwent surgical removal of the changes and the histological
examination showed a benign teratoma in excised tumor tissue.
Conclusions: The FM is mainly self-limited disorder but in some case developing of polymyositis and recurrences were described. In chosen patients treatment with steroids and cytotoxic agents was proposed. The coexistence of vertebral canal tumor and the FM has not been described yet.

Keywords: focal myositis, spine canal, tumor