nearly , 90% of metastatic tumors occur in jaw bones , especially premolar - molar region of the mandible , whereas metastases to soft tissues are extraordinarily rare and account for 0.1% of all oral malignancies .
most metastatic tumors to the orofacial region are seen in patients aged between 40 and 70 years .
metastasis to the soft tissues mostly involves gingiva and alveolar mucosal sites ( 54% ) followed by tongue ( 30% ) . in some cases ,
oral metastatic tumors are found to be the first sign of metastatic spread and in some instances ; they are an indication for unidentified primary tumor of the distant site .
the primary site differs according to oral site colonization . in men , primary tumor of the lung followed by the prostate gland and kidney
the breast is the most common primary tumor site affecting the jawbones and soft tissues ( 41% and 24.3% , respectively ) , followed by the adrenal and female genital organs .
clinically , these metastatic lesions appear nonaggressive , mimicking reactive or benign lesions or even simple odontogenic infections . the clinical features of these lesions include a bony swelling with tenderness , pain , ulcer , hemorrhage , paresthesia and pathological fracture .
it is important to diagnose the origin of the tumor as the management will depend significantly on the histological type .
although infrequent , oral metastases are rarely encountered as the first sign of occult cancer .
hence , this article emphasizes on detailed dentoalveolar examination and early diagnosis for finding the primary focus of metastatic tumor .
a 60-year - old male patient presented with a swelling in the right lower back teeth region of the jaw since 3 months [ figure 1 ] .
the patient complaints of pain for 10 days , radiating to the right temporal region .
the patient was a known hypertensive since 4 years . a well - defined solitary swelling present on the right side of mandible on extraoral examination , a well - defined , solitary swelling measuring 4 cm
 5 cm was noted on the right side of the mandible , which was hard in consistency and fixed to the underlying skin .
no other pathologic findings were noticed during physical examination . on intraoral examination , firm ,
nontender swelling with ill - defined borders measuring 3 cm  3 cm was noted in the right mandibular premolar - molar region [ figure 2 ] .
there was no ulceration , paresthesia or pathological fracture . on intraoral examination , firm ,
nontender swelling with ill - defined borders measuring 3 cm  3 cm was noted patient was advised for oral pantamograph and computed tomography ( ct ) scan .
ct scan of the face with three - dimension reconstruction revealed a well - defined osteolytic lesion involving the ramus and body of the right half of the mandible , measuring 54 mm  45 mm  50 mm ( anterioposterior  transverse  craniocaudal ) .
it showed speculated periosteal lesion with multiple irregular calcifications and extended into the lingual and mandibular soft tissues [ figure 3 ] .
based on the clinical presentation , a differential diagnosis of inflammatory swelling , odontogenic cyst , odontogenic tumor , soft tissue tumor or metastatic tumor to the jawbones was given .
computed tomography scan of the face with three - dimensional reconstruction revealed a well - defined osteolytic lesion with multiple irregular calcifications that extended into the lingual and mandibular soft tissues incisional biopsy was done for the histopathological diagnosis .
histopathological examination of the h and e stained tissue showed diffuse fibrous connective tissue stroma invaded by the tumor cells which were cuboidal to short columnar with eosinophilic cytoplasm arranged in alveolar / follicular pattern of varying sizes [ figure 4 ] .
bony trabeculae were evident in some areas [ figure 5 ] . based on these features ,
the lesion was diagnosed as a metastatic malignant tumor , probably metastasizing from the lung .
( h&e stain , 100 ) tumor islands along with few bony trabeculae were evident in some areas .
( h&e stain , 40 ) x - ray chest posterior - anterior view revealed consolidation of the right lower zone [ figure 6 ] .
the ct scan of the chest with contrast revealed dense soft tissue mass lesion with speculated margins and focal pleural thickening noted at the right posterior basal segment .
x - ray chest posterior - anterior view revealed consolidation in right lower zone of the lungs treatment for the patient was palliative external beam radiotherapy on linac given to a total dose of 3000 cgy in 10 fractions to jaw by rl / ll for 12 days which was well - tolerated by the patient .
chemotherapy included injection cisplatin ( 75 mg)-intravenous ( iv ) ; injection etoposide ( 150 mg)-iv ; tablet vomiset ( 8 mg ) ; tablet ultracet .
the common primary sources of tumors metastatic to the oral region are the breast , lung and kidney .
the actual incidence of these cancers is unknown since oral metastatic disease is usually a manifestation of advanced disease .
the mean age of occurrence is 54 years with slight male predilection . in our case ,
also the patient was aged about the same age ( 60 years ) as supported in the literature .
most of the patients are aware of primary tumors before the metastatic spread to the oral cavity . in our case ,
the most common primary sites for oral metastases were the lung , kidney , liver and prostate for men ; breast , female genital organs , kidney , and colorectum for women . in our case too , lung was found to be the primary site .
the clinical presentation of the metastatic lesions differed between the various oral sites . in the jawbones ,
most of the patients complain of rapidly progressing swelling , pain , paresthesia , difficulty in chewing , dysphagia , disfigurement and bleeding .
our patient presented with features such as firm , nontender swelling with ill - defined borders .
there was no paresthesia , difficulty in chewing , dysphagia , bleeding and pathological fracture .
pathogenesis of oral metastasis is unclear but thought to be a multistage process in which cells detach themselves from the primary tumor and get transported by lymphatic or blood vessels .
recent studies state that cancer cells metastasizing to bone have shown to alter the physiologic balance between both bone resorption and bone formation .
treatment of oral metastasis depends upon its presentation and the stage during which it has been identified .
management includes chemotherapy , radiotherapy , surgical excision or a combination of the techniques under local anesthesia .
an average survival time for lung cancer metastasis is 4 months to 1 year with a maximum survival rate of 5 years .
 oral cavity is an uncommon site for metastasis and is usually an evidence of widespread disease . 
 the clinical presentation of the metastatic lesions differs between the various sites in the oral region . 
 metastatic tumors account for 13% of all oral malignancies . 
 the jawbones , particularly the mandibular molar area is more frequently affected than the oral soft tissues ( 2:1 ) . here , we report a case of a 60-year - old male patient with metastasis from lung to the mandible , where the metastasis was detected before primary tumor . 
INTRODUCTION
CASE REPORT
DISCUSSION
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