We describe a primary leiomyosarcoma of bone located in the distal fibula in a 67- year-old man. Plain radiographs and computer tomography scan revealed a lytic destructive lesion in the distal metaepiphyseal region of the left fibula with little involvement of the surrounding soft tissues. The lesion was composed of proliferating spindle-shaped cells with very slim cytoplasm and narrow oval cigar shaped nuclei. Immunohistochemistry studies demonstrated a strong positivity for actin and desmin, and weak positivity for caldesmon.
Keywords: Bone tumors; Distal fibula; Primary leiomyosarcoma.