metastasis to the spinal cord is uncommon and the actual number varies from 0.9 to 2.1% for autopsied cancer patients to as much as 3.9% in other studies of which nearly 50% arise from primary lung cancer . a case of intramedullary lung metastasis to the conus has been reported only once earlier in english literature . a 46-year - old male had presented with progressive paraparesis associated with sensory impairment in both lower limbs since 2 months . he had incontinence of urine and stool . at the time of presentation he had flaccid paraplegia with a sensory level at 11 dorsal vertebral level ( d11 ) . one month prior to presentation to us , the patient had undergone an unsuccessful attempt at excision of the conus mass . magnetic resonance imaging ( mri ) of the dorsolumbar spine showed a discrete homogenously enhancing mass within the conus at the d12 level [ figure 1 ] . the tumor was seen as on the earlier scan as it had not been biopsied . a posterior midline myelotomy was performed on the conus at the site of the tumor bulge . a grey colored firm mass was noted . a gross total excision of the tumor could be achieved . there was cellular and nuclear atypia , mitotic activity , pleomorphism along with scattered bizarre cells . post - contrast sagittal magnetic resonance ( mr ) image of dorsolumbar spine shows a discrete intramedullary conus tumor opposite d12 vertebra post - contrast sagittal mr image of dorsolumbar spine shows the conus tumor and posterior laminectomies after first surgery photomicrograph showing large polyhedral epithelial cells with vesicular nuclei , prominent nucleoli , and glassy eosinophilic cytoplasm . ( hematoxylin and eosin ( h and e ) , 400 ) the patient underwent a positron emission tomography - computed tomography ( pet - ct ) scan of the whole body that revealed hypermetabolic activity in the hilum of the right lung . a review of the chest radiograph showed a right hilar lung mass , which had been missed earlier [ figure 4 ] . chest radiograph demonstrates a right hilar mass the patient was advised chemotherapy for the primary and radiotherapy for the secondary spinal metastasis . at 1 month the majority of tumors of the spine are extradural , with 55% occurring predominantly in the vertebral bodies and epidural fat . of these tumors , metastases are the majority , with primary bone tumors being less common . the opposite is found in the spinal cord , with metastasis to the cord being very rare . among these lesions , iscm are rare , comprising only 0.5% of spinal axis metastases . the most common intramedullary spinal cord metastasis is lung ( 64% ) , followed by breast ( 11% ) , melanoma ( 5% ) , renal cell cancer ( 4% ) , colon - rectal ( 3% ) , lymphoma ( 3% ) , and the remaining undiagnosed primary . the lesions are found most often in patients with concomitant brain metastasis . in patients without history of systemic neoplasia such as the patient in our report , a knowledgeable clinical evaluation coupled with selected laboratory and diagnostic imaging investigations may delineate primary or secondary spinal malignant lesions from other more benign differential diagnostic entities . mri is useful in determining the extent of cns involvement which may affect the therapeutic decision making in many patients . these metastases are found at all levels of the spinal cord as follows : cervical ( 42% ) , thoracic ( 26% ) , and lumbar region ( 32% ) . of the several hundred reported cases of iscm , the incidence of metastasis to the conus medullaris is very rare and our literature search has yielded only five cases . of these five , there have been four cases of lung carcinoma metastasis to the conus , one case report in the english literature by guppy and wagner , another case in the french literature by faillot et al . , and two cases in the japanese literature by tashima et al . ramakonar et al . , have described the only case of periurethral adenocarcinoma metastasis to the conus medullaris . primary intramedullary tumors tend to be slow growing ; however , metastasis have rapid growth associated with progressive neurological deterioration as in the present patient . the neurological presentation of conus medullaris involvement is varied from myelopathy , radiculopathy , and myeloradiculopathy . paraplegia , paresthesia , sensory changes , erectile dysfunction , and bladder dysfunction have been described as the initial presentation of tumors occurring at the conus medullaris . because of its close proximity to the cauda equina , some involvement of spinal nerve roots can be involved with presentation of unilateral symptoms initially . the most probable route of tumor spread include : hematogenous seeding via the arterial system or batson 's venous plexus ; leptomeningeal invasion from embolic seeding via cerebrospinal fluid ; direct extension through dura mater or nerve roots ; or lymphatic spread from contiguous vertebral metastasis . in this patient , a lung adenocarcinoma iscm at c4-c5 had an acute presentation of brown - sequard syndrome . schijns et al . , have presented a case in whom symptoms from an intramedullary metastasis from renal cell carcinoma preceded the detection of the primary tumor . microsurgical excision of the conus medullaris mass , not only provides tissue for histopathological diagnosis , but also allows early recovery of neurological function . this could be attributed to resolution of the mass effect as well as edema causing tumor . faillot et al . , advocated radical removal of intramedullary metastasis to the conus medullaris because it can improve the quality and comfort of life , although , as pointed out , it does not affect the survival duration . isla et al . , on the other hand , have advocated partial resection with the goal of preserving existing function as the best choice for treatment . when the patients general condition is good , surgery can relieve pain and preserve or stabilize neurologic function . with recent advances in the treatment of cancer , depending on the primary tumor , some of these patients life expectancy can be long . in general , however , most of these patients have already had significant systemic involvement by the time it has reached the spinal cord . schiff and oneill , in reviewing 40 patients with spinal cord metastasis , found a median survival of 6 months for surgery and radiation , versus 4 months for those only receiving radiotherapy . their finding was consistent with that of grem et al . , who found that more than 80% of patients died within 3 months after diagnosis of iscm . in conclusion , metastasis to the conus medullaris is rare and may be the first manifestation of a primary cancer . rapid progression of neurological symptoms should warrant reimaging and may indicate metastasis to the spinal cord , especially in patients with previously diagnosed cancer . pet - ct of the whole body may detect small lesions before they become symptomatic as well as detect clinically unknown primaries . though the prognosis for iscm patients is poor , early detection and appropriate treatment of such cancer patients may ameliorate symptoms and prolong good quality life .
a 46-year - old male presented with progressive paraparesis and sensory impairment in both lower limbs since 2 months . 
 he had urinary and bowel incontinence . on examination he had flaccid paraplegia with a sensory level at 11th dorsal vertebral level . 
 magnetic resonance imaging ( mri ) scans of the lumbosacral spine showed an enhancing intramedullary lesion in the conus . 
 the patient underwent excision of the conus mass . 
 histopathology confirmed the tumor to represent a poorly differentiated metastatic carcinoma from an unknown primary . a positron emission tomography - computed tomography ( pet - ct ) scan of the whole body revealed hypermetabolic activity in the hilum of the right lung confirmed to be a lung carcinoma on a ct - guided biopsy . 
 the patient was undergoing chemoradiation at 1 month follow - up . 
 the author 's literature search has yielded only four other case reports of conus metastasis of which only one is in english literature . the present case report and review of literature are presented .