John R. Parker

Choroid Plexus Carcinoma

Choroid plexus carcinoma is an uncommon neoplasm of the central nervous system most commonly found in the pediatric population. It is associated with a dismal prognosis, especially if incompletely resected. Accurate histopathologic diagnosis is imperative, and this neoplasm should always be included in the differential diagnosis of a papillary intraventricular tumor. Histopathologic features include blurring of papillary architecture, layers of neoplastic choroid plexus epithelial cells with pleomorphic nuclei, increased nuclear-to-cytoplasmic ratio, increased mitotic activity, areas of necrosis, and brain invasion. Current accepted treatment is gross total surgical resection of the tumor as the goal. Use of adjuvant chemotherapy is controversial at this time; however, it is considered in some cases.

Isocitrate dehydrogenase 1 R132H mutation is not detected in angiocentric glioma

Mutations of isocitrate dehydrogenase-1 gene (IDH1), most commonly resulting in replacement of arginine at position 132 by histidine (R132H), have been described in World Health Organization grade II and III diffuse gliomas and secondary glioblastoma. Immunohistochemistry using a mouse monoclonal antibody has a high specificity and sensitivity for detecting IDH1 R132H mutant protein in sections from formalin-fixed, paraffin-embedded tissue. Angiocentric glioma (AG), a unique neoplasm with mixed phenotypic features of diffuse glioma and ependymoma, has recently been codified as a grade I neoplasm in the 2007 World Health Organization classification of central nervous system tumors. The present study was designed to evaluate IDH1 R132H protein in AG. Three cases of AG were collected, and the diagnoses were confirmed. Expression of mutant IDH1 R132H protein was determined by immunohistochemistry on representative formalin-fixed, paraffin-embedded sections using the antihuman mouse monoclonal antibody IDH1 R132H (Dianova, Hamburg, Germany). Known IDH1 mutation-positive and IDH1 wild-type cases of grade II to IV glioma served as positive and negative controls. All 3 patients were male, aged 3, 5, and 15 years, with intra-axial tumors in the right posterior parietal-occipital lobe, right frontal lobe, and left frontal lobe, respectively. All 3 cases showed characteristic morphologic features of AG, including a monomorphous population of slender bipolar cells that diffusely infiltrated cortical parenchyma and ensheathed cortical blood vessels radially and longitudinally. All 3 cases were negative for the presence of IDH1 R132H mutant protein (0/3). All control cases showed appropriate reactivity. IDH1 R132H mutation has been described as a common molecular signature of grade II and III diffuse gliomas and secondary glioblastoma; however, AG, which exhibits some features of diffuse glioma, has not been evaluated. The absence of mutant IDH1 R132H protein expression in AG may help further distinguish this unique neoplasm from diffuse glioma.

Cortical restricted diffusion as the predominant MRI finding in sporadic Creutzfeldt-Jakob disease

Creutzfeldt-Jakob disease is a rare and fatal neurodegenerative disorder with MR findings predominantly limited to the grey matter of the cortex and the basal ganglia. Sporadic Creutzfeldt-Jakob disease can produce a spectrum of MR imaging findings of the brain, most notably on DWI and FLAIR sequences. Involvement of the basal ganglia and neocortex is the most common finding, but isolated involvement of the cortex can also be seen. We describe the clinical history and MRI findings of three patients with sporadic Creutzfeldt-Jakob disease confirmed by brain biopsy or autopsy and review the literature of imaging manifestations of this disease.

46-YEAR-OLD MAN WITH A SPINAL CORD MASS

Medulloblastoma accounts for only 1% of all adult CNS tumors. Likewise, recurrence of adult medulloblastoma greater than 20 years after initial diagnosis is extremely rare.We describe a case of adult medulloblastoma with late relapse of disease. The patient was 24 years old when first diagnosed and was treated with total tumor resection and craniospinal radiation. At the age of 45, an enhancing 1.3 cm intradural extramedullary spinal cord lesion at T5 was discovered on MRI. This was presumed to be recurrent medulloblastoma in the form of drop metastasis and the patient was treated with spinal radiation. Several months following treatment, at the age of 46, a follow-up MRI demonstrated an enhancing 1.4 cm intradural extramedullary spinal cord lesion at T7. The lesion was resected and histopathologic examination was most consistent with medulloblastoma, late drop metastasis. Although rare, adult medulloblastoma recurring 20 years after initial diagnosis should always be considered in the main differential diagnosis when working up CNS lesions at or outside the primary tumor site.

Atypical Cells in the Cerebrospinal Fluid of a 43-Year-Old Man With Perioral Parasthesias

1. What is (are) this patient’s most striking clinical and laboratory findings? 2. How do you explain the patient’s most striking clinical and laboratory findings? 3. What is this patient’s most likely diagnosis? 4. What is the characteristic clinical presentation of an individual with this patient’s condition? 5. What are the criteria for making this diagnosis? 6. What is the pathogenesis of this patient’s disease? 7. What is the prognosis for this patient? 8. What treatment options are available for this patient’s condition? 9. How did performing a cell count on the CSF contribute to this case?