schwannoma also called as neurilemmoma is a benign neoplasm of the schwann cells surrounding the nerves . . however , intraosseous schwannoma are extremely rare in jaw bones and represent less than 1% of benign primary tumors of the jaws . a 42-year - old man hailing from dakshina kannada district in karnataka , india , reported to us with a slowly growing swelling on the left side of lower jaw since the previous 4 years . three years ago teeth in the same region became loose and were extracted at a primary health center . the patient had visited the same health center a number of times because of the swelling . medications were prescribed each time but there was no decrease in the size of the swelling . a diffuse swelling was observed on the left lower third of the face extending to the left submandibular region with normal overlying skin . intraoral examination revealed bicortical expansion of the edentulous ridge in the same region with reduced buccal sulcus depth . residual cyst , fibro - osseous lesion , ameloblastoma , dentigerous cyst , and odontogenic keratocyst were listed as the possible differential diagnoses . a mandibular lateral occlusal radiograph was made , which showed buccolingual expansion in the same region and orthopantomogram revealed the presence of large radiolucent area ( 5  7 cm ) on the left side of the mandible involving the body and ramus [ figure 1 ] . a sclerotic rim extending 1 cm below the lower border of the mandible was observed . anteriorly the lesion extended to the distal aspect of premolar and posteriorly to the ramus . a biopsy was performed from the intraoral site , middle of the mandibular residual alveolar ridge and evaluated histopathologically . it revealed the presence of spindle - shaped cells with elongated nuclei arranged in typical circular ( antoni a ) and linear pattern ( antoni b ) along with small cyst - like spaces and eosinophilic verocay bodies [ figure 2 ] . based on these histopathologies , it was diagnosed as schwannoma . since the lesion was massive and only a thin margin of the base was intact , which could lead to pathological fracture , the entire left segment of the mandible was resected barring the condyle . the left side was then reconstructed with bone plate and stabilized with interdental wiring for 3 weeks before being discharged from the hospital . the patient was followed - up for 6 months during which the patient had of localized numbness on the left side of the lower lip . the patient was also advised prosthetic rehabilitation but failed to keep up with further appointments . ( left side ) mandibular lateral occlusal radiograph revealing buccolingual expansion of the body of mandible on the left side . ( right side ) orthopantomogram showing large radiolucent area in the left body and ramus region of mandible photomicrograph ( hematoxylin and eosin stain ; original magnification 100 ) showing cells with elongated spindle - shaped nuclei ( antoni a type ) and also homogenous acellular areas ( verocay bodies ) a recent review of literature revealed that only 44 cases of intrabony schwannomas have been reported . three possible mechanisms of bone involvement by schwannoma have been explained : ( 1 ) a tumor may arise within the bone ; ( 2 ) a tumor may arise within the nutrient canal and produce canal enlargement ; or ( 3 ) a peripheral tumor causing bone enlargement . in our case a combination of the first 2 mechanisms could be the cause of bone involvement . in most of the reported cases the same nerve was involved in our case on the left side of the mandible . radiographically schwannomas present as well - defined unilocular radiolucency with sclerotic borders but sometimes features , such as cortical expansion , root resorption , spotty calcification , and peripheral scalloping can be evident . microscopically spindle - shaped cells in antoni a and antoni b arrangement interspersed with hyalinized verocay bodies are characteristic features . surgical treatment was carried out in our patient , which is the most widely used method to prevent recurrence . intraosseous schwannoma although extremely rare , knowledge of the clinical radiological and histopathological features is extremely important for prompt diagnosis and appropriate management .