Synovial sarcoma of the mandible
A 76-year-old man was referred to Oral and Maxillofacial Pathology Department of Tehran University of Medical Sciences, Iran, in February, 2011, with a progressive swelling in the left side of his face of 1-month duration. He also complained of dull pain in the same region and paresthesia of the left half of the lower lip. Clinical examination revealed bony hard, nontender swelling of the posterior region of the mandibular body. Also, submandibular lymph nodes at the same side were enlarged and palpable. No other intra-oral sign was observed and no significant event was noted in his past medical history. A conventional panoramic radiograph showed ill-defined destruction of the posterior mandibular body and ascending ramus []. A computed tomography (CT) scan revealed a destructive lesion at the same region.\nAn incisional biopsy was performed under local anesthesia. Histopathologic examination of the specimen showed a relatively uniform neoplasm composed almost entirely of spindle cells with irregular, moderately to highly cellular patterns []. Neoplastic cells showed mild pleomorphism and scattered atypical mitotic figures, with no evidence of necrosis []. Based on clinical, radiographic, and histopathologic findings, an initial diagnosis of “malignant spindle cell tumor” was made. Also, a panel of immunohistochemical staining was applied. Odontogenic and nonodontogenic fibrosarcoma, neurogenic sarcoma, angiosarcoma, intraosseous spindle cell carcinoma, and atypical Ewing sarcoma were considered in the differential diagnosis.\nTumor cells were positive for vimentin, cytokeratin (AE1/ AE3), CD99, Bcl2, and Ki-67 (more than 25%; all by Dako Co., Tehran, Iran) and negative for smooth muscle actin (SMA) and S100 (all by Dako Co., Tehran, Iran; Figures -). A final diagnosis of “monophasic synovial sarcoma” was made accordingly. The patient was referred to the department of oral and maxillofacial surgery for further management which consisted of hemimandibulectomy with levels I–III cervical lymphnode dissection. The histopathologic examination of the whole specimen confirmed our previous diagnosis. Also, metastatic tumor involvement was observed in one lymph node in level II and one in level III. The patient died 2 months later because of extensive metastasis to the lungs.