favorable prognostic factors of brainstem glioma include the presence of neurofibromatosis , relatively younger age at diagnosis , exophytic components , focal lesion and calcification on computed tomography , histopathology grades . however , prolonged survival is very infrequent . authors report an extremely uncommon case of brainstem glioma , which underwent surgery 21-years back for pilocytic astrocytoma of the midbrain and also received gamma knife therapy . he presented with hemiplegia due to bleed in hemi - midbrain possibly due to gamma knife - induced arteriopathy . a 34-year - old male presented with sudden - onset hemiplegia and altered sensorium . important history included left temporal craniotomy and microsurgical decompression of a focal midbrain mass lesion , pilocytic astrocytoma , who grade i in the year 1993 . , he also underwent cerebrospinal fluid ( csf ) diversion surgery due to associated hydrocephalus , and medium pressure ventriculoperitoneal ( vp ) shunt placement was carried out . in 1995 , he underwent re - exploration surgery and removal of residual mass lesion . during the follow - up period after the second surgery , he was doing well , except a small recurrent lesion was observed in magnetic resonance imaging ( mri ) , for which he received gamma knife therapy in 2002 . at present admission evaluation on admission revealed a glasgow coma scale ( gcs ) of e2v2m5 with left - sided facial nerve paresis of lower motor neuron type along with left - sided hemiplegia . mri of the brain on admission revealed an infarct in the hemi - midbrain showing hypointense signal on the t1-weighted image . it was showing restriction of diffusion in the diffusion - weighted images [ figure 1 ] , hypointense signal on t2-weighted image [ figures 2 and 3 ] . he was electively ventilated for 1 week , and tracheostomy was performed for pulmonary toileting . he was gradually weaned off from the ventilator and discharged with a gcs of e4vtm6 and walking with support accepting oral feed and continuing daily activity of living with support . magnetic resonance imaging of the brain of 34-year - old male , diffusion - weighted axial section image showing hypointense lesion in the right half of the midbrain the cranial magnetic resonance imaging , axial section , t2-weighted image showing hypointense lesion in the right half of the midbrain magnetic resonance imaging of the brain , coronal section t2-weighted image showing lesion in the right half of the midbrain with hypointense signal intensity brain stem glioma is one of the common tumors in pediatric age group . depending on histopathology , it can be categorized as un who grade i , ii , iii , or iv . brainstem gliomas can further also be categorized into following groups , on the basis of neuroimaging features , i.e. , diffuse , exophytic - focal , intrinsic - focal , cervicomedullary , and types based on radiological features . usually , diagnosis is finally based on histopathological features analyzed in relation to the imaging study 's findings . various treatment modalities of brain stem glioma are highly variable and including forms a spectrum of approaches including , stereotactic biopsy , resection alone or combined with adjuvant therapy for suboptimally resected mass , or supervised observation with serial imaging study or adjunctive csf diversion therapy like vp shunt surgery followed by primary radiation therapy , chemotherapy in different combinations depending on respectability of lesion , clinical status of patient , experience of surgical team , availability of adjuvant therapy facility . stereotactic biopsy of brainstem mass is other minimally invasive surgical option to obtain tissue for final histopathological and immunohistochemistry graqding and typing selvapandian et al . observed grade ii astrocytoma being the most common variety in their series of 92 cases , who underwent stereotactic biopsy . however , in addition to primary surgery , many cases may need vp shunt surgery to treat hydrocephalus , which develops secondary to obstruction in csf flow pathway due to the growth of brain stem mass . although brainstem gliomas carry poor prognosis and shorter life expectancy , few patients may have prolonged survival . interestingly , our case is unique as he survived for 21 years after histopathological confirmation after diagnosed as brainstem glioma . prognostic factors affecting survival in the brainstem glioma include age at diagnosis , histopathological type and who grade , extent of surgical resection , adjuvant therapy , focal or diffuse lesion , requirement for vp shunt , and associated comorbid illness . reported a case of pilocytic astrocytoma who received gamma knife therapy 17-years back developed rapid tumor growth during pregnancy necessitating emergency surgery and histopathological diagnosis was pilocytic astrocytoma . however , only partial resection was possible as it was infiltrating the brainstem parenchyma . however , our case presented at the current admission with infarct of hemi - midbrain , which can be attributed to bleed in residual tumor or due to an effect of gamma knife therapy . gamma knife therapy is known to cause arteriopathy not only in the tumor bed but also in the adjoining regions of the brainstem . however , it remains a speculation , if it was bleeding due to malignant transformation which can occur de novo by conversion into higher grade with neoangiogenesis leading to tumor bleed . however , a biopsy would have clearly demonstrated the exact nature of cause and histopathological diagnosis . however , more evidence lies in favor of radiation - induced arteriopathy following gamma knife therapy as there is a uniform restriction of diffusion in diffusion - weighted mri study images . brainstem glioma usually carries a bad prognosis and prolonged survival is very infrequent . in a detailed pubmed , medline search for prolonged survival , authors could get the longest survival only up to 17-years , reported by umehara et al . , who was subjected to gamma knife therapy without preoperative histopathological confirmation . she , later on , got symptomatic , mri brain revealed large tumor growth during pregnancy necessitating emergency surgery , and histopathological diagnosis was pilocytic astrocytoma was only made 17 years after the first clinical presentation . a total of 58 cases of brainstem glioma were managed by authors . of these cases , our case is interesting as he underwent first surgery about 21 years back , for brain stem glioma , in the year 1993 , underwent surgical re - exploration for recurrence , and also received gamma knife therapy . following gamma knife therapy , he was doing well with good physical and cognitive performance and independently managing automotive spare parts shop and he presented with sudden - onset left - sided hemiplegia on the current admission . the cranial mri imaging revealed an infarct involving right hemi - midbrain , contrast mri brain revealed no residual glioma . to the best of our knowledge , such prolonged survival is not reported with a case of histopathologically proven pilocytic astrocytoma of brain stem , who survived 21 years with nonresidual tumor on the last imaging study and probably developed hemiplegia due to bleed , highlighting bleed as delayed complication following gamma knife therapy for cranial tumors and represents first case of its kind reported in the literature . although brainstem glioma carries a poor prognosis , a few cases may report prolonged survival , highlighting the hope for prolonged disease - free survival as in the current case . hence , these cases may exhibit better response with multimodalities treatment with close supervision . as our cases needed gamma knife surgery as well as csf diversion surgery for residual lesion and progressive obstructive hydrocephalus , respectively , every case of brainstem glioma developing new neurological deficit during the follow - up period warrants at least mri brain as investigation modality of choice to exclude not only tumor recurrence but also to exclude infarct and delayed radionecrosis , and these may be representing sequelae of radiation therapy .
brainstem glioma usually carries a poor prognosis and prolonged survival is very infrequent . in a detailed pubmed , medline search for prolonged survival , authors could got a longest survival only up to seventeen years , reported by umehara et al , who was subjected to gamma knife therapy and got symptomatic , mri brain reveled large tumor growth during pregnancy necessitating emergency surgery and histopathological diagnosis was pilocytic astrocytoma . 
 authors report an interesting case of midbrain glioma diagnosed 21 years back , who underwent gross resection in the year 1993 , histopathology was pilocytic astrocytoma , who grade i , and received gamma knife surgery for residual subsequently and he presented with sudden onset left sided hemiplegia on the current admission . 
 the cranial mri imaging revealed an infarct involving right hemi midbrain , contrast mri brain revealed no residual glioma . to the best knowledge of authors such prolonged survival 
 is not reported with a case of brainstem glioma survived twenty- one years with non residual tumor on the last imaging study represents first case of its kind in the western literature and probably developed hemiplegia due to bleed , highlighting bleed as delayed complication following gamma knife therapy for cranial tumors