Mandibular intraosseous schwannoma in a child: Report of a rare case
The patient was a 9-year-old boy who was referred to the Department of Oral and Maxillofacial Pathology of the Isfahan University of Medical Science 5 months ago, while complaining about a swelling in the inferior border of the right mandible. There were no associated symptoms like pain and paresthesia. Deviation of anterior teeth and looseness of teeth (D, E) were seen.\nIn the panoramic radiograph, radiolucency with sclerotic border from mesial of tooth 36 to distal of 3C and transposition of first and second impacted premolar was observable [].\nAxial computed tomography scan revealed a unilacular lesion in the left mandibular body, 2.5 × 3 cm in size, with a well-defined border, marked expansion and thinning of the buccal and lingual cortical plates [].\nFirst, on the basis of clinical and radiographic features, we can suggest the following lesions: Keratocystic odontogenic tumor, central giant cell granuloma, unicystic ameloblastoma and ameloblastic fibroma.\nNo any special problem in both family history and routine hematologic tests was observed. Excisional biopsy was performed and irregular masses of solid tissues were observable during biopsy.\nIn the histopathology features, ovoid to spindle shape and epithelioid cells were identified, some of which indicated slight pleomorphism and hyperchromatism. The cells showed, in some of the regions, a palisading arrangement. Besides, some regions showed intracellular edema and degenerative changes. In some parts, numerous blood vessels and perivascular hyalinization were identified, and typical capsule was not evident [].\nBased on histopathologic features, several differential diagnoses were first taken into account: Benign fibroblastic tumor, benign neural tumors and neoplastic vascular lesions.\nIn order to reach final diagnosis, immunohistochemical staining was carried out. The findings revealed that the intensity of S100 staining was 4+ and those of Ki67 was weak and 10% at most []. According to these studies and immunohistochemistry, and regarding clinical and radiographic features and hematoxylin and eosin, in which there were some regions similar to Antoni A with palisading cells and similarities of some regions to Antoni B, we reached the final and definite diagnosis of the lesion.\nAfter 4 months, the patient was evaluated by taking panoramic radiography, and it seems that reparative process is running within the lesion [].