This case is a good example of how some benign osseous processes can mimic malignancy.

The initial images show an exophytic calcified mass and there was at first a concern for malignancies such as parosteal osteosarcoma or periosteal chondrosarcoma.

On biopsy, however, no malignancy was found, and the mass has decreased in size over time. The overall appearance and presentation is compatible with nodular fasciitis.