Sarcomas are a rare heterogeneous group of neoplasms of mesenchymal origin. In the redistribution of all head and neck malignancies, sarcomas are represented by only 1%. Herein, we report a case of a 66-year-old patient with right maxillary sinus sarcoma that spread through the ostiomeatal complex, infiltrated the septum, all ethmoid cells, frontal sinus, involved the entire right nasal cavity and penetrated to the nasopharynx. Patient was treated with neoadjuvant chemotherapy, surgery and adjuvant radiotherapy. The histopathology indicated poorly differentiated sarcoma with elements of Ewing’s sarcoma, but also with elements consistent with osteosarcoma. Molecular pathological analysis excluded Ewing's sarcoma. Samples were also sent for review to the other Pathology Clinics. They suggested poorly differentiated high-grade pleomorphic sarcoma with elements of osteosarcoma. The accurate diagnosis of the head and neck sarcoma type can be a histopathology dilemma posing a great challenge in the choice of therapeutic approach, and thus the treatment outcome.