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 .
 schwannoma , a benign nerve sheath tumor is relatively rare in occurrence and even rarer in sites , such as jaw bones . 
 there are only 45 reported cases of intraosseous schwannoma of the jaws reported in the literature . 
 we report a rare case of mandibular schwannoma in a 50-year - old indian male . 
 the clinical features resembled that of a residual cyst , fibro - osseous lesion or an odontogenic tumor / cyst . 
 radiological differential diagnoses of ameloblastoma or odontogenic keratocyst was made based on the findings of the orthopantomogram . the lesion was examined histopathologically and a final diagnosis of schwannoma arising from the inferior alveolar nerve was made . 
 the aim of this report is to add information to the existing sparse literature on intraosseous schwannomas of the jaw . 
Introduction
Case Report
Discussion
Conclusion