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Using conventional magnetic resonance imaging (MRI) methods, the differentiation of primary central nervous system lymphoma (PCNSL) and glioblastoma (GBM) is often difficult due to overlapping imaging characteristics. This study aimed to evaluate the diagnostic value of combining 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) with arterial spin labeling (ASL) for differentiating PCNSL from GBM. In all, 20 patients with PCNSL and 55 with GBM were retrospectively examined. From the FDG-PET data, the maximum standardized uptake values (SUVmax) and the ratio of tumor to normal contralateral gray matter (T/N_SUVmax) were calculated. From the ASL data, the T/N ratio of the maximum tumor blood flow (relative TBFmax: rTBFmax) was obtained. Diagnostic performance of each parameter was analyzed using univariate and multivariate logistic regression analyses and receiver-operating characteristic (ROC) curve analyses. A generalized linear model was applied for comparing the performance of FDG-PET and ASL individually, and in combination. In univariate analysis, SUVmax and T/N_SUVmax were statistically higher in patients with PCNSL and rTBFmax was higher in patients with GBM. In the multivariate analysis, T/N_SUVmax and rTBFmax were statistically independent. The sensitivity, specificity, and area under the curve (AUC) for discriminating PCNSL from GBM were 100%, 87.3%, and 0.950 in T/N_SUVmax; 90%, 72.7%, and 0.824 in rTBFmax; and 95%, 96.4%, and 0.991 in the combined model, respectively. The combined use of T/N_SUVmax and rTBFmax may contribute to better differentiation between PCNSL and GBM.

Background: Diffuse midline glioma (DMG) is an invasive astrocytic tumor arisen from midline structures, such as the pons and thalamus. Five cases of DMG in the pineal region have been reported, but the clinical course was poor; there was no case of survival for more than 2 years.Case Description: We report the case of a 12-year-old boy with DMG in the pineal region who is living a normal daily life for more than 6 years following multimodal treatment. He complained of a headache accompanied by vomiting that had gradually worsened 1 month previously, and initial magnetic resonance imaging revealed a pineal tumor. Germinoma was initially suspected; however, a combination of chemotherapy using carboplatin and etoposide was ineffective. The first surgery was performed through the left occipital transtentorial approach (OTA); the diagnosis was DMG. After 60 Gy radiotherapy concomitant with temozolomide (TMZ), the tumor enlarged. Second surgery was performed through bilateral OTAs, and 90% of the tumor was removed. In addition, stereotactic radiotherapy (30 Gy, six fractions) was administered, and the local equivalent dose in 2 Gy/fraction reached 97.5 Gy. Maintenance chemotherapy using TMZ and bevacizumab was continued for 2 years. After finishing chemotherapy, the enhancing lesion enlarged again, and bevacizumab monotherapy was effective. Now, at 6 years after diagnosis, the patient leads an ordinary life as a student.Conclusion: Maximum resection and high-dose radiotherapy followed by bevacizumab may have been effective in the present case.

Giant pituitary adenomas carry significant surgical risks when treated with transsphenoidal approaches or the transcranial approach alone. Combined transsphenoidal and transcranial approaches have been reported; however, removing adenomas extending into the third ventricle may still be challenging. We report a case of giant pituitary adenoma expanding into the third ventricle, which was removed using a combined transventricular preforniceal approach and an endoscopic endonasal transsphenoidal surgery (ETSS). A 41-year-old man with headache, nausea, and a 1-week history of a visual field defect was transferred to our hospital. He had a disturbed left visual acuity, right homonymous hemianopia, and choked disc in both eyes. Preoperative magnetic resonance imaging revealed a giant pituitary adenoma with a maximum diameter of 55 mm extending from the intrasellar to the suprasellar region, thus occupying the entire third ventricle and causing hydrocephalus. The space between the anterior commissure and the fornix was expanded. The foramen of Monro was shifted backward due to compression by the tumor. He underwent maximum surgical resection using a combined transventricular preforniceal approach and ETSS. Considering technical demands and reliability, the intra- to suprasellar parts were removed by ETSS while the intraventricular part was removed through the preforniceal approach. The residual tumor in the right cavernous sinus and behind the anterior communicating artery was treated with stereotactic radiotherapy. One year after the operation, the patient leads an independent life. The combined technique of the preforniceal approach and ETSS provided a direct view of the entire third ventricle and hemostasis in the present case.

The efficacy of stereotactic radiotherapy (SRT) has been well established for postoperative residual and recurrent nonfunctioning pituitary adenomas (NFPAs). However, the risk of visual impairment due to SRT for lesions adjacent to the optic pathways remains a topic of debate. Herein, we evaluated the long-term clinical outcomes of hypofractionated stereotactic radiotherapy (HFSRT) for perioptic NFPAs. From December 2002 to November 2015, 32 patients (18 males and 14 females; median age 63 years; range, 36–83 years) with residual or recurrent NFPAs abutting or displacing the optic nerve and/or chiasm (ONC) were treated with HFSRT. The median marginal dose was 31.3 Gy (range, 17.2–39.6) in 8 fractions (range, 6–15). Magnetic resonance imaging (MRI) and visual and hormonal examinations were performed before and after HFSRT. The median follow-up period was 99.5 months (range, 9–191). According to MRI findings at the last follow-up, the tumor size had decreased in 28 (88%) of 32 patients, was unchanged in 3 (9%), and had increased in 1 (3%). The successful tumor size control rate was 97%. Visual functions remained unchanged in 19 (60%) out of 32 patients, improved in 11 (34%), and deteriorated in 2 (6%). Two patients had deteriorated visual functions; no complications occurred because of the HFSRT. One patient developed hypopituitarism that required hormone replacement therapy. The result of this long-term follow-up study suggests that HFSRT is safe and effective for the treatment of NFPAs occurring adjacent to the ONC.

This paper reports on a case of pilocytic astrocytoma (PA), for which a diagnosis by conventional pathological diagnosis was difficult but an accurate diagnosis was possible by a new molecular diagnostic method. A 13-year-old girl whose tumor developed by a headache that gradually worsened, and a well-demarcated T2-hyperintense lesion was found in the left cerebellum by a magnetic resonance imaging while the apparent diffusion coefficient value was also high. While the finding was a typical PA, histological features of PA were not found in the surgical specimen. An initial diagnosis was anaplastic astrocytoma (AA), and the final diagnosis through a central review was diffuse astrocytoma (DA). On the other hand, using MethylationEPIC (850 K) array, an analysis by a DNA methylation-based tumor classifier tool as reported by Capper et al. showed that this case belonged to a methylation class of PA. The copy number profile calculated from the methylation array data showed hints of BRAF/KIAA1549 fusion and no other chromosomal alterations, which also supported the molecular diagnosis. The patient was treated with local radiotherapy concomitant with temozolomide based on the initial pathological diagnosis during the consultation, but maintenance temozolomide therapy was not done according to the final molecular diagnosis. The tumor showed no recurrence for 20 months. In this case, the integrated diagnostic approach based on histological and molecular findings was clinically significant to select proper adjuvant treatment. It is crucial that the usefulness and robustness of this new molecular diagnostic method be validated further.