Localized plantar amyloidosis: case report and review of the literature.

Amyloidosis may be hereditary or acquired and the deposits can be focal, localized, or systemic in distribution. A discrete mass of amyloid deposition is called an amyloidoma and is the least common presentation. Soft tissue amyloidoma in an extremity is exceedingly rare. Amyloidomas can mimic malignant neoplasms both clinically and radiologically. We report a case of an amyloidoma in the foot, which has not been previously described. Clinical history, pathology, and immunohistochemistry and appearance by MRI are described. Knowledge of this atypical lesion, in its various forms, is important for experts in musculoskeletal radiology, pathology, surgery, and oncology to appreciate as it can prevent confusion with more sinister disease processes such as malignancy. Early recognition can help guide appropriate management in a timely fashion.