Mandibular primitive neuroectodermal tumor in an adult dog

This is the report of a mandibular neuroectodermal/ewing sarcoma in an 8-year-old male cross breed dog that is unique because of tumor origin location. Pedunculated, ulcerative, firm 6.0 x 4.0 x 5.5 cm tumor mass effaced the bone at the rostral part of the mandible and had a white-sanguineous color at cross section appearance. Histopathologically, small round blue cell tumor was diagnosed. Immunohistochemically, tumor cells were positive for vimentin, S100 and Glial fibrillary acidic protein [GFAP] and negative for neuron specific enolase [NSE] and desmin. Mandibular location is a rare event in these types of tumors