they usually arise in the skull base and especially in the sphenopetrosal , sphenoclival or petroclival junctions . they tend to engulf cranial nerves or major arteries and become symptomatic with cranial nerve palsies or headaches . they grow slowly and are considered benign as opposed to their malignant relatives the chondrosarcomas . the histological differentiation between the two can be challenging and has enormous significance regarding their therapy . a 19-year old male was admitted with complains of headache , hyperventilation and new onset of focal seizures . there was no significant family history , especially no history of tumor . the patient received no medication and had no history of radiation therapy . on clinical examination the patient was in postictal recovery and presented a paresis of the left upper extremity . magnetic resonance imaging ( mri ) scan revealed a giant mass in the right precentral gyrus measuring 566 cm ( figure 1a and b ) . the corticospinal fibers as well as the motoric areas in the precentral gyrus were displaced anteriorly and posteriorly around the tumor ( figure 1c - e ) on mri imaging the tumor mass showed intermediate signal intensity on t1 weighted and high signal intensity on t2 weighted images as well as heterogeneous enhancement with typical honeycomb appearance . the partially involved dura and the tumor were dissected from the cortical surface without difficulty . the intracranial mass was completely removed in a piecemeal fashion . since the bone did not seem to be involved in the tumor process we drilled the inner table of the calvaria but did not remove the bone completely . the removed tumor mass was macroscopically multinodular , ivory colored with a very cartilaginous consistency ( figure 2 ) . the postoperative computed tomography ( ct ) brain scan confirmed the total excision of the tumor ( figure 4a ) . he was discharged on the 12 postoperative day . following gross total resection and after establishment of the histological diagnosis no adjuvant therapy was needed . the whole body scintigraphy did not show further tumors ( figure 4b and c ) . chondromas are recognized as a dyschondroplasia caused by developmental errors in enchondral ossification and are slow - growing , benign tumors of cartilaginous origin . they originate in the skull base and especially arise from the sphenopetrosal , sphenoclival or petroclival junctions . rarely , they can be seen in the parasellar region , at the falx or arousing from the dura convexity . multiple theories have been suggested to explain the genesis of these tumors . in their paper colpan and colleagues listed four of them : i ) metaplasia of meningeal fibroblasts ; ii ) multipotential or perivascular mesenchymal cells in the dura mater ; iii ) aberrant nests of cartilage forming cells in the dura mater ; iv ) traumatic displacement of cartilage . they can be found as solitary lesions or as part of ollier s disease ( multiple polysystemic enchondromatosis ) or maffuci s syndrome ( multiple enchondromatosis associated with soft tissue angiomas ) . the oldest patient that has been described was 55 years old , whereas most of the patients had symptoms in a young age . the neurological symptoms that the patients developed depended on the localization of the tumor and were usually epileptic seizures or motor deficits . delgado - lopez et al . published a patient with noonan s syndrome and chondroma , a combination which was never described before . no adjuvant therapy is then needed . since intracranial chondromas are rare tumor entities , there are no grade 1 recommendations regarding their treatment . in all patients that were surgically treated and where the tumor was completely resected , no recurrence occurred . in our patient and after macroscopically complete tumor resection we planned the next mri scan 6 months postoperatively . the further mri scans will then be scheduled in one , two and five years or earlier , if symptoms appear . the diagnostic work- up includes mri and ct sequences . in the contrast enhanced mri images the tumor appears ringlike with intratumoral nodular enhancement and no edema . in the computed tomography nonetheless , a definitive diagnosis can only be made after histological examination of the tumor . the initial diagnosis was suspicious for chondrosarcoma and therefore the histological specimen was sent to a specialized reference center . histopathological analysis revealed a monomorphous tumor of low - moderate cellularity surrounded by a fibrous pseudocapsule . the tumor cells were strongly positive for s100 and negative for cytokeratine , gfap , and ema . other tumors that have to be considered in the differential diagnosis are meningiomas , hemangiopericytomas , gliomas and metastases . immunohistochemistry is an important tool in establishing the diagnosis . since chondromas are benign tumors and grow slowly , they are only then symptomatic , when the mass effect affects vital functions of the brain . sugiura et al . performed a molecular analysis in their case of convexity chondroma which revealed wild type idh1/2 and expression of hmga2 . our patient presented with symptoms of focal mass effect and high intracranial pressure as well as seizures . as a result , we preferred a gross total resection over a possible stereotactic biopsy in order to alleviate the symptoms and to obtain a permanent histological diagnosis . because of its huge size we also did not consider biopsy and radiosurgery as an option . since the tumor was located in the eloquent precentral region , we preoperatively performed a digital tractography ( fibertracking ) and a functional mri , which showed displacement of the fibers posteriorly and anteriorly to the tumor . since the tumor was well defined and did not diffusely infiltrate the neighboring fibers gross total resection was feasible . the diagnostic work- up includes mri and ct sequences . in the contrast enhanced mri images the tumor appears ringlike with intratumoral nodular enhancement and no edema . in the computed tomography nonetheless , a definitive diagnosis can only be made after histological examination of the tumor . the initial diagnosis was suspicious for chondrosarcoma and therefore the histological specimen was sent to a specialized reference center . histopathological analysis revealed a monomorphous tumor of low - moderate cellularity surrounded by a fibrous pseudocapsule . the tumor cells were strongly positive for s100 and negative for cytokeratine , gfap , and ema . other tumors that have to be considered in the differential diagnosis are meningiomas , hemangiopericytomas , gliomas and metastases . immunohistochemistry is an important tool in establishing the diagnosis . since chondromas are benign tumors and grow slowly , they are only then symptomatic , when the mass effect affects vital functions of the brain . sugiura et al . performed a molecular analysis in their case of convexity chondroma which revealed wild type idh1/2 and expression of hmga2 . our patient presented with symptoms of focal mass effect and high intracranial pressure as well as seizures . as a result , we preferred a gross total resection over a possible stereotactic biopsy in order to alleviate the symptoms and to obtain a permanent histological diagnosis . because of its huge size we also did not consider biopsy and radiosurgery as an option . since the tumor was located in the eloquent precentral region , we preoperatively performed a digital tractography ( fibertracking ) and a functional mri , which showed displacement of the fibers posteriorly and anteriorly to the tumor . since the tumor was well defined and did not diffusely infiltrate the neighboring fibers gross total resection was feasible . supratentorial dural chondromas are rare lesions that grow slowly and cause symptoms due to local mass effect or increased intracranial pressure . if they are located in eloquent brain areas , a thorough diagnostic imaging should be performed including functional imaging and fibertracking in order to pick the best possible approach with no or minimum manipulation of the critical structures . the histological diagnosis can be challenging , but once established no adjuvant therapy has to be undertaken .
chondromas usually affect the small bones of hand and feet and account for only 0.5% of all intracranial tumors . 
 we present a case of a giant , supratentorial meningeal chondroma in a 19-year old male patient and discuss the preoperative diagnostic findings as well as the appropriate treatment options . a 19-old male presented with headache , new onset of focal seizures and paresis of left upper extremity . 
 magnetic resonance imaging revealed a large right parietal tumor in the precentral region with local mass effect . 
 the patient underwent right parietal craniotomy and gross total resection of the tumor . 
 the histopathological report revealed a chondroma . 
 intradural supratentorial chondromas are extremely rare . as with other slow growing intracranial masses , 
 they often reach a relatively large size before generating symptoms . 
 maximal surgical resection is the treatment of choice and if this is achieved no adjuvant therapy is necessary .