Neuroimaging of Unusual Glioblastoma Using Diffusion Tensor Imaging

Background: Gliosarcoma refers to an uncommon astrocytic tumor of the central nervous system. These tumors include both glial and mesenchymal components by definition, and are extremely malignant. Gliosarcomas are particular to tumors with distinct gliomatous and sarcomatous constituents, and are distinguished from gliobastomas which have undergone mesenchymal metaplasia. Gliosarcomas encompass 2-8% of all glioblastoma cases and tend to occupy the supratentorial regions of the brain, especially the temporal lobe. Rare infratentorial lesions including the cerebellar hemisphere, intraventricular, and multi-focal tumors have also been reported. Accurate neuroimaging diagnosis is critical and diffusion tensor imaging (DTI) and spectroscopy can be useful to differentiate from inflammatory disease. Methods: We report a 38 year-old Caucasian male with a right parietal lobe glioblastoma. The patient presented with new onset tonic-clonic seizures lasting approximately five minutes associated with postictal confusion and incontinence. The patient had conventional brain MRI scans including DTI. MRI data was processed to obtain tractography and fractional anisotropy (FA) maps. MR images were examined for location and extent of tumor as well as invasion, destruction or displacement of brain parenchyma and white matter tracts. Results: Noncontract CT revealed no abnormality and emergent MR imaging shows a ring-enhancing lesion measuring 3.1x2.2x3.1 cm at the junction of the right parieto-occipital region. The lesion abuts the dural surface, characteristic of gliosarcoma. Extensive surrounding edema causing complete effacement of the posterior horn of the right lateral ventricle, parietal effacement of the anterior floor of the right ventricle, and a 1.2 cm right to left midline shift were observed. Mild diffuse enhancement in the region of the splenium of the corpus callosum was likely compatible with seizure activity. Increased signal intensity of axial FLAIR image was seen in this area after four weeks. Fractional anisotropy is reduced at the tumor site suggesting an aggressive and invasive lesion. Diffusion tensor tractography shows destruction of white matter tracts compatible with destruction rather than invasion of parenchyma. Histopathology confirms gliobastoma multiforme, demonstrating mixed glial and sarcomatous components. However, GFAP was strongly positive in both areas and a reticulin stain was not increased in the sarcomatorus areas excluding the sarcomatous variant of glioblastoma. Conclusion: We report the imaging findings of a rare gliosblastoma radiographically presenting as a gliosarcoma due to its location along the dural surface, but with lack of pathologic findings. Gross total tumor resection was performed and the patient and is undergoing adjuvant radiation therapy with concurrent chemotherapy

Human herpesvirus multiplex ddPCR detection in brain tissue from low- and high-grade astrocytoma cases and controls.

BACKGROUND: Glioblastoma (GBM) is a fatal CNS malignancy, representing 50 % of all gliomas with approximately 12-18 months survival time after initial diagnosis. Recently, the human herpesvirus cytomegalovirus (CMV) has been suggested to have an oncogenic role, yet this association remains controversial. In addition, human herpesvirus 6 (HHV-6) and Epstein-Barr virus (EBV) have also been associated with low-grade gliomas, but few studies have examined HHV-6 and EBV in glioblastomas. Droplet digital PCR (ddPCR) is a highly precise diagnostic tool that enables the absolute quantification of target DNA. This study examines the association between multiple human herpesviruses and astrocytomas. METHODS: This study analyzed 112 brain tissue specimens, including 45 glioblastoma, 12 astrocytoma grade III, 2 astrocytoma grade II, 4 astrocytoma grade I, and 49 controls. All brain tissue samples were de-identified and pathologically confirmed. Each tissue block was sectioned for DNA extraction and CMV, EBV, HHV-6A and HHV-6B, and a cellular housekeeping gene were amplified by ddPCR. RESULTS: Neither CMV nor HHV-6A were detected in any of the astrocytoma samples. However, HHV-6B (p = 0.147) and EBV (p = 0.049) had a higher positivity frequency in the GBM compared to the controls. CONCLUSION: The undetectable CMV DNA in the astrocytoma cohort does not support the observation of an increased prevalence of CMV DNA in GBM, as reported in other studies. EBV has a significantly higher positivity in the GBM cohort compared to the controls, while HHV-6B has a higher but not statistically significant positivity in the case cohort. Whether these viruses play an oncogenic role in GBM remains to be further investigated

Suprasellar Epidermoid Cyst Originating from the Infundibulum: Case Report and Literature Review.

Epidermoid cysts account for a small fraction of intracranial brain tumors, most commonly found in the cerebellopontine angle and parasellar cisterns. Here we present a rare case of an epidermoid cyst located in the suprasellar region, specifically originating from the infundibulum. Only one additional case with an epidermoid cyst originating within the pituitary stalk has been previously reported in the literature. The patient in this case presented with headaches, diplopia and blurred vision without any endocrinopathy. The patient\u27s pre-operative evaluation was significant for pseudotumor cerebri, hyponatremia, obesity, and a history of smoking; post-operative course was significant for neurogenic diabetes insipidus

ALK-Positive Primary Central Nervous System Anaplastic Large T-Cell Lymphoma: A Unique Case Presentation

Anaplastic large cell lymphoma (ALCL) is a rare T-cell lymphoma usually ALK+ and presenting in immunocompetent young adults and children with a female preponderance. Central nervous system (CNS) involvement of ALCL T-cell lymphoma is extremely rare; approximately 30 cases are reported in the literature, mostly in male patients of Korean and Japanese ancestry and involving the parietal and frontal lobes. We report a unique case of ALK+ ALCL in an Asian woman and predominantly involving the occipital lobe. The patient, an immuno-competent 18-year-old woman with a recent history of viral meningitis, presented with left-sided vision changes. Magnetic resonance imaging showed a mass in the medial left occipital gyrus, with no evidence of disease outside the CNS. The patient underwent stereotactic biopsy of the mass. Histopathologic sections showed neural tissue with perivascular cuffing and diffuse parenchymal and leptomeningeal infiltration of discohesive, pleomorphic predominantly large cells with abundant cytoplasm, round to irregular nuclei, dispersed chromatin, and prominent nucleoli. Immunohistochemistry showed that the large cells were positive for CD3, CD7, CD8, ALK1, CD25, EMA, granzyme B, and CD30, which confirmed the diagnosis of ALK+ primary CNS ALCL. Interphase FISH hybridization studies were positive for ALK-associated translocation t(2;5). Because of the rarity of this lymphoma, the pathogenesis, prognostic factors, and treatment strategies have not been well studied, except for ALK positivity, which is associated with a good prognosis. We believe this case will be a unique addition to the cases previously reported in the literature on this extremely rare lymphoma

Human herpesvirus multiplex ddPCR detection in brain tissue from low- and high-grade astrocytoma cases and controls.

BACKGROUND: Glioblastoma (GBM) is a fatal CNS malignancy, representing 50 % of all gliomas with approximately 12-18 months survival time after initial diagnosis. Recently, the human herpesvirus cytomegalovirus (CMV) has been suggested to have an oncogenic role, yet this association remains controversial. In addition, human herpesvirus 6 (HHV-6) and Epstein-Barr virus (EBV) have also been associated with low-grade gliomas, but few studies have examined HHV-6 and EBV in glioblastomas. Droplet digital PCR (ddPCR) is a highly precise diagnostic tool that enables the absolute quantification of target DNA. This study examines the association between multiple human herpesviruses and astrocytomas. METHODS: This study analyzed 112 brain tissue specimens, including 45 glioblastoma, 12 astrocytoma grade III, 2 astrocytoma grade II, 4 astrocytoma grade I, and 49 controls. All brain tissue samples were de-identified and pathologically confirmed. Each tissue block was sectioned for DNA extraction and CMV, EBV, HHV-6A and HHV-6B, and a cellular housekeeping gene were amplified by ddPCR. RESULTS: Neither CMV nor HHV-6A were detected in any of the astrocytoma samples. However, HHV-6B (p = 0.147) and EBV (p = 0.049) had a higher positivity frequency in the GBM compared to the controls. CONCLUSION: The undetectable CMV DNA in the astrocytoma cohort does not support the observation of an increased prevalence of CMV DNA in GBM, as reported in other studies. EBV has a significantly higher positivity in the GBM cohort compared to the controls, while HHV-6B has a higher but not statistically significant positivity in the case cohort. Whether these viruses play an oncogenic role in GBM remains to be further investigated