The authors present an unusual case of a leiomyosarcoma of the distal tibia. Leiomyosarcoma tumors typically originate from smooth muscle tissue. It is rare for it to derive from bone and even rarer to be found in a bone of the lower limb. Given this extreme rarity in addition to nonspecific findings on plain film radiographs and magnetic resonance imaging (MRI), biopsy was needed in this case. It was only through immunochemistry staining that a definitive diagnosis was made. As such, this case is an illustrative example of an aggressive, though rare, primary lesion of the bone which should be considered in the differential diagnosis of a lytic intramedullary lesion. This case also highlights the need for careful evaluation of imaging features suggesting a potentially aggressive lesion requiring appropriate work up in a timely fashion.