Toshihiro Kumabe

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Autoimmune hypophysitis very rarely spreads to nearby organs outside the pituitary tissue, for unknown reasons, with only 5 reported cases of hypophysitis spreading over the cavernous sinus.

Object: The atrium of the lateral ventricle is often affected by tumors, and some patients with these tumors suffer neurological deficits, including hemiparesis after surgery. The authors of this study investigated the possible mechanisms causing the relatively high incidences of ischemic complications associated with surgery approaching the atrium of the lateral ventricle. Methods: Clinical records and radiological images of 28 patients were retrospectively studied. These patients had their lateral ventricles opened at the atrium during the resection of gliomas as well as other nonbenign brain tumors, and were treated for gliomas at our tertiary referral center in the Tohoku district, Japan, between January 2008 and December 2010. Results: Routine postoperative diffusion-weighted MR images obtained within 72 hours after surgery detected infarction in the periatrial/periventricular regions in 7 patients, presumably corresponding to the lateral posterior choroidal artery (LPChA) territory. Five of these 7 patients suffered neurological sequelae with varying severities. The choroid plexus at the atrium was coagulated to achieve hemostasis during the surgery in all of these patients. Detailed analysis of microangiograms revealed ventriculofugal arteries arising from the lateral ventricle. Damage of the subependymal artery that supplies the ventriculofugal arteries caused by coagulation of the choroid plexus at the atrium probably resulted in the infarction in these patients. Conclusions: Neurosurgeons must be aware of the possibility of LPChA territory infarction during surgery in the atrial or periatrial regions caused by subependymal artery obstruction after manipulating or coagulating the choroid plexus near the atrium.

Dysembryoplastic neuroepithelial tumors (DNETs) have conventionally been regarded as benign and stable tumors and considered curable with surgery without adjunctive therapy. Recently, recurrent DNETs with or without malignant transformation have been described. The authors report 2 unusual cases of DNET: 1) an enlarging lesion that developed an enhancing component over the natural course of 4 years, and 2) a recurrent DNET that developed an enhancing component 10–11 years after gross-total resection. The patient in the first case was treated with subtotal resection and adjuvant radiochemotherapy; histological examination of the tumor led to the diagnosis of DNET, WHO Grade I, for the nonenhancing component and anaplastic oligodendroglioma, WHO Grade III, for the enhancing component. The patient in the second case was treated with repeat gross-total resection; the original tumor had been histologically diagnosed as DNET, and the nonenhancing and enhancing components of the recurrent tumor were diagnosed as simple and complex forms of DNET, respectively. These and previous reports suggest an aggressive subtype of DNETs. If follow-up MRI reveals progressive behavior, resection should be performed without delay. Additional radiochemotherapy is needed if the histological diagnosis demonstrates malignant transformation.

A 3-year-old boy with Williams syndrome associated with supravalvular aortic stenosis was admitted to our hospital with disturbance of consciousness and a 2-month history of truncal ataxia. T1-weighted magnetic resonance imaging with contrast medium showed a heterogeneously enhanced tumor in the right cerebellum with severe hydrocephalus. The patient underwent tumor resection via suboccipital craniotomy. At the end of resection of the tumor, sudden cardiac arrest occurred after ST segment elevation. Despite immediate cardiopulmonary resuscitation, the patient died. Histological examination of the cerebellar tumor revealed that the tumor consisted of monomorphous bipolar spindle cells on a background of myxoid matrix, and angiocentric arrangement without Rosenthal fibers or eosinophilic granular body. The final diagnosis was pilomyxoid astrocytoma.

Changes in histological and genetic characteristics were investigated in 18 paired primary and recurrent oligodendroglial tumors, using sequencing analysis for isocitrate dehydrogenase (IDH) 1 and 2 gene mutation, Ki-67 and p53 immunohistochemistry, and fluorescent in situ hybridization for loss of heterozygosity of chromosomes 1p and 19q (1p/19q co-deletion). Malignant transformation occurred in 5 of 8 cases with World Health Organization (WHO) grade II tumors, but in 0 of 10 cases with WHO grade III tumors progressing to glioblastoma. Thirteen of the 18 cases carried IDH1 gene mutation. Tumors with IDH1 mutation tended to survive for longer, even after recurrence, but newly developed microvascular proliferation, tumor necrosis, and elevated Ki-67 labeling index were common. Eleven of the 13 IDH1-mutation tumors had either 1p/19q co-deletion or nuclear expression of p53, but all 5 IDH1/2 wild-type tumors had neither. All cases had the same profile for 1p/19q status at recurrence, but nuclear expression of p53 changed from negative to positive in 2 of 6 cases with IDH1 mutation and 1p/19q co-deletion. WHO grade II oligodendroglial tumors show a high rate of malignant transformation, possibly involving p53 in tumors with IDH1 mutation and 1p/19q co-deletion. Tumors with IDH1 mutation had a more aggressive histological phenotype despite their better prognosis.

The objective of this study was to determine the outcome of central nervous system primitive neuroectodermal tumors (CNS PNETs) and to clarify the histopathological findings as prognostic factors. We performed a retrospective analysis of nine consecutive patients with CNS PNETs who underwent treatment at our institute between 1993 and 2011. All patients were treated by surgical resection followed by chemoradiotherapy. Additional treatment, including surgical resection, was performed at relapse. Expression of immunohistochemical markers was examined for neuronal, astrocytic, mesenchymal, and epithelial differentiation, and also for TP53, O⁶-methylguanine-DNA methyltransferase, and Ki-67. Five-year progression-free survival was 18.2 % and the overall survival was 52.5 %. Five the 9 patients had recurrence and 4 patients died during the median follow-up period of 41.1 months. All 4 patients died of dissemination not local recurrence. After relapses, the extent of differentiation was different in each case and TP53 changed to positive or negative, but the Ki-67 labeling index did not reveal any differences between primary and recurrent tumors. A treatment procedure to prevent and treat dissemination of CNS PNETs should be established. Because the pathological change after relapse was different in each case, definitive histopathological prognostic factors for CNS PNETs are still difficult to propose.

Treatment for medulloblastoma consists of surgical resection, radiation therapy, and chemotherapy. In Japan, ICE chemotherapy consisting of cisplatin, ifosfamide, and etoposide is one of the most common regimens. Here, we summarize the toxicity and efficacy of ICE chemotherapy and evaluate the usefulness of the recently introduced molecular classification scheme to predict the outcome.