undifferentiated sarcomas , formerly known as malignant fibrous histiocytomas ( mfh ) , are usually identified in the soft tissue of the extremities and trunk21013 ) . a literature review of intracranial undifferentiated sarcomas , including the formerly used less - specific term mfh , identified less than three dozen cases reports since 1976 691216 ) . among these case reports of intracranial sarcomas , intracranial sarcomas developed after radiosurgery in three cases 111214 ) and after chemotherapy in one case1 ) . these reports suggest that intracranial undifferentiated sarcomas can be derived by the transformation of other tumors of the nervous system . however , the exact mechanism and risk factors remain undefined . here , we report our experience in managing a rapidly growing intracranial undifferentiated sarcoma in a young adult who was initially diagnosed with a low - grade glioma . to the best of our knowledge , this is the first report of undifferentiated sarcoma arising from low - grade glioma without any chemotherapy or radiotherapy . brain magnetic resonance ( mr ) imaging revealed an intra - axial , non - enhancing solitary lesion in the right frontal lobe , which was hyperintense on fluid - attenuated inversion recovery ( flair ) imaging ( fig . mr spectroscopy ( mrs ) demonstrated a prominent choline ( cho ) peak and a reduction in n - acetyl - aspartate ( naa ) ( fig . a stereotactic biopsy specimen was obtained from the area that showed the highest cho / naa ratio ( approximate value of 2.0 ) . histopathological tests identified a diffuse astrocytoma [ world health organization ( who ) grade ii ] . as per the parent 's wishes of postponing any further tumor removal , the patient was discharged at that point of time . brain mr imaging showed a right frontal mass with strong enhancement and central necrosis ( fig . a hypervascular , friable , intraparenchymal mass was identified , and gross total removal was achieved ( fig . one month later , he was discharged and was followed - up with outpatient adjuvant radiotherapy . however , five months after tumor removal , he visited the emergency room with severe headache . two months later , he died of severe brain herniation caused by extensive regrowth and bleeding of the intracranial sarcoma ( fig . although the tumor tissue showed atypism and higher cellularity than normal brain tissue , there was no mitosis , necrosis , or vascular proliferation ( fig . 4a ) . on immunohistochemistry , staining for gfap and s100 protein were negative ( fig . although the tumor tissue showed atypism and higher cellularity than normal brain tissue , there was no mitosis , necrosis , or vascular proliferation ( fig . 4a ) . on immunohistochemistry , staining for gfap and s100 protein were negative ( fig . according to the latest who classification , the tumor case presented here can be classified as an undifferentiated sarcoma3 ) . undifferentiated sarcomas can present as round cells , spindle cells , epithelioid cells , or pleomorphic cells and do not resemble any mature tissue4 ) . because undifferentiated sarcoma is a novel entity , a literature search of previous reports was performed by using the formerly used term " mfh " . radiologically , intracranial undifferentiated sarcomas resemble high - grade gliomas , which may present with heterogeneous contrast enhancement , central necrosis , and surrounding edema15 ) . in our patient , perilesional edema was not severe , but the heterogeneous rim enhancing pattern and previous histopathological report suggested a high - grade glioma , and follow - up computed tomography imaging demonstrated recurrent tumor bleeding . we concluded that the mr imaging findings of the undifferentiated sarcoma reflected the aggressive nature of the tumor . the tumor was locally progressive without any evidence of distant metastasis . despite the repeated tumor resections , recurrence and bleeding caused by the rapid growth of the tumor resulted in the fatal outcome . although the histopathological findings are similar , we opine that intracranial undifferentiated sarcomas are a different entity from extracranial sarcomas . based on the previous reports , the mean age of the intracranial sarcoma cases was 38.7 years9 ) while our patient was 23 years old ; the mean age in the extracranial cases was reported to be approximately 60 years27 ) . since extirpation of intracranial tumors is more difficult , the survival period of the intracranial undifferentiated sarcoma is much shorter . in the review of 32 intracranial mfhs by mitsuhashi et al.9 ) , most of the patients with intracranial mfh died within 1 year from diagnosis . in contrast , the overall 5-year survival of primary undifferentiated sarcomas arising from the extremities has been reported to be over 70%27 ) . one of the possible explanations of how this uncommon sarcoma arises from low - grade glioma is pre - existing heterogeneity of two pathologies since the initial tumor diagnosis . minimal invasive biopsy surgery is limited in its scope , and there is a possibility of sampling error . the rapidly growing undifferentiated tumor might supersede the comparatively slow growth of low - grade glioma in later stages . the initial mr images and tumor tissue obtained by stereotactic biopsy did not show any findings suggesting a high - grade tumor . although there are no references on this kind of mechanism in the literature , few investigators have speculated the potential role of wounds in oncogenesis . hofer et al.5 ) , in an animal study , reported the increased tumor growth after surgical wounding . meng et al.8 ) , described that wounds can be a risk factor for cancer by means of oncogene activation in wound healing process . according to the literature on undifferentiated sarcomas of extremities , radical resection of the tumor is the treatment of choice and chemotherapy and radiotherapy are also helpful in lowering the recurrence rate210 ) . however , in cases of intracranial undifferentiated sarcomas , authors have reported recurrence and poor prognosis after recommended treatment . chemoradiotherapy shows temporary improvement but does not change the prognosis dramatically6911 ) . in our case , the patient received adjuvant radiotherapy after the first resection of the sarcoma . it is known that subtotally resected low - grade gliomas can transform to high - grade tumors , and in cases of undifferentiated sarcoma , the course is rapid and fatal . rapidly growing refractory intracranial tumors are challenging for neurosurgeons . although it is not usual , sporadic reports about malignant transformation by radiation , chemotherapy , and surgical trauma suggest that the early tumor resection is more ideal in young adults . this is the first report of undifferentiated sarcoma arising from low - grade glioma without radiation or any other antitumor therapy . we hope this report will provide information for a better understanding of the pathophysiology of undifferentiated sarcomas .
undifferentiated sarcomas are rarely identified in the intracranial region . 
 a 23-year - old man was admitted with a chief complaint of headache . 
 initial magnetic resonance images showed signs of low - grade glioma in the frontal lobe . 
 stereotactic biopsy was performed , and a diagnosis of diffuse astrocytoma was confirmed . 
 three months later , the patient presented with a high - grade tumor as seen on imaging studies . 
 he underwent total resection of the tumor and histopathological tests identified an undifferentiated sarcoma . 
 the patient died eight months later due to massive tumor bleeding . to the best of our knowledge , 
 this is the first report of undifferentiated sarcoma arising from low - grade glioma without any chemotherapy or radiotherapy .