Giant chondroid syringoma presenting as a growing subcutaneous mass in the upper arm: MRI findings with pathologic correlation.

Chondroid syringoma of skin is a rare type of soft tissue tumor originating from the sweat glands. We report a documented case of giant chondroid syringoma occurring in the upper arm, which developed over the course of one year. The radiographic, sonographic, MR imaging, gross pathologic, and histologic findings of the tumor are described. Because the clinical suggestion of such a tumor was low, we present the imaging appearances of chondroid syringoma that could be used to make a presumptive diagnosis, and discuss the many entertained differential diagnostic possibilities.