Extraskeletal mesenchymal chondrosarcoma in the axillary region: reports of two cases.

Extraskeletal mesenchymal chondrosarcomas (EMCs) are relatively uncommon, and a location in the upper extremity, especially in the shoulder or axillary region, is rare. Furthermore, the radiographic findings of EMCs do not show any features that distinguish them from other neoplasms, and therefore, definitive diagnoses are made based on histological features. EMC is an aggressive tumor with a poor prognosis, and requires wide surgical excision. However, its treatment may involve peculiarities such as a difficulty in obtaining a proper surgical margin in the axillary region or shoulder. In this report, the authors present two rare cases of EMCs in the axillary region.