Unusual Presentation of Foreign Body Granuloma of the Foot After Sharp Injury Mimicking a Malignant Lesion: A Case Report.

Foot foreign body granulomas can mimic malignancies, especially when the history and unusual location pose a diagnostic dilemma. We report the case of a 33-year-old male with delayed-onset progressive swelling over the foot dorsum after a sharp injury through the plantar aspect of the foot. The unusual presentation and radiolucency warranted further radiologic evaluation, which revealed a benign foot swelling. An excision biopsy and histopathologic examination revealed a rubber body granuloma. No recurrence of the granuloma was noted during the 11-month follow-up period after removal of the offending agent. The nature of the injury, immunologic response to the rubber fragment, and lack of infection led to the delayed presentation at an unusual site, mimicking malignancy. Rubber body granuloma has rarely been reported in published studies. A high index of suspicion of retained radiolucent fragments and astute radiologic evaluation with magnetic resonance imaging are required for management of sharp injuries occurring through footwear. We reviewed the approach for evaluating such cases of foot swelling that can mimic malignancies.