Gamma Knife Radiosurgery: An Adjuvant Therapy for Primary Sellar Paraganglioma.

Sellar paraganglioma (SP) is a rare benign tumor, usually treated by surgery. SPs are lobulated, firm, adherent, and highly vascular, allowing mostly partial resection. We present the case of a 52-year-old man diagnosed with primary SP, treated with a transcranial-transsphenoidal (TC-TS) surgical approach, followed by adjuvant Gamma Knife stereotactic radiosurgery (GKSR). The tumor has an extra-pituitary origin, with a sellar-suprasellar, right cavernous sinus extension that encroached the bilateral optic nerve and anterior cerebral artery. Histopathology confirmed SP with a Zellballen pattern. Despite postoperative tumor growth observed at four and 10 months, a stable residual tumor was noted at a follow-up two years after GKSR. SP is diagnosed mainly in middle age or in adolescent males. The TC-TS approach offers a bidirectional view that allows greater resection by minimizing blind spots, thus reducing complications. Similar to the paragangliomas of other sites, the efficacy of GKSR was observed for primary SP. SP is a rare differential diagnosis of pituitary diseases; however, it should be considered. After surgical resection of primary SP, GKSR is observed as an effective adjuvant therapy.

Solitary Fibrous Tumor or Hemangiopericytoma of the Sella in an Older Patient Treated with Partial Removal Followed by Fractionated Gamma Knife Radiosurgery.

Solitary fibrous tumor (SFT) or hemangiopericytoma (HPC) is a rare fibroblastic tumor of mesenchymal origin. SFT or HPC comprises <1% of all primary central nervous system tumors. SFT or HPC of the sellar or suprasellar region is even more unusual. We herein report a sellar SFT or HPC in an octogenarian who achieved favorable progress with partial removal followed by fractionated gamma knife radiosurgery. An 87-year-old woman presented with occasional headache and visual field defects. A rapidly growing tumor of the sella turcica was diagnosed. The patient underwent endoscopic transnasal transsphenoidal surgery; however, only partial resection of the tumor was possible, as it was fibrous and hard with increased vascularity. A histological examination confirmed the tumor to be grade II SFT or HPC. Two months after the resection, the residual tumor grew rapidly. Given the patient's advanced age, re-surgery was not the preferred option; thus, fractionated gamma knife radiosurgery (marginal dose, 30 Gy in five fractions) was performed. MRI and visual field examination performed 3 months after irradiation revealed tumor shrinkage and improvement in the visual field, respectively. One year and three months after irradiation, the tumor continued to shrink and her visual field had improved. Taking age into consideration, partial resection with fractionated gamma knife radiosurgery was the more appropriate choice for both local tumor control and the safety of the optic apparatus.

A case of impaired consciousness due to large cystic metastatic brain tumors from lung adenocarcinoma successfully controlled with Ommaya reservoir placement.

Large cystic brain metastases from lung cancer are rare but cause substantial central nervous system symptoms that often deprive patients of opportunities to receive anticancer therapy. There are no standard therapeutic strategies against this relentless condition. Here we report a patient with large cystic brain metastases from lung adenocarcinoma successfully controlled with Ommaya reservoir placement and subsequent gamma knife surgery (GKS). A 62-year-old Japanese man presented with left upper extremity paresis. Magnetic resonance imaging revealed large cystic masses in both cerebral hemispheres and multiple brain nodules. Computed tomography of the chest showed irregular nodular shadows in the lower lobe of the right lung with multiple swollen lymph nodes. His performance status (PS) and level of consciousness worsened rapidly. Thus, at that time, we could not perform bronchoscopy with the goal of establishing a pathological diagnosis. Intracystic placement of an Ommaya reservoir followed by GKS dramatically improved his PS and level of consciousness. We were subsequently able to perform bronchoscopy, which resulted in a diagnosis of lung adenocarcinoma with 100% positivity of programmed cell death-1 ligand-1 expression. The patient was started on a 3-week cycle of pembrolizumab. Substantial reduction in tumor size was observed after one course of pembrolizumab treatment. The patient had a partial remission. He has been still receiving pembrolizumab with long-term efficacy. In conclusion, our report suggests that aggressive Ommaya reservoir placement should be considered for large cystic metastatic brain tumors, even in patients with undiagnosed cancer, poor PS, and impaired consciousness.

Sex Differences in Gamma Band Functional Connectivity Between the Frontal Lobe and Cortical Areas During an Auditory Oddball Task, as Revealed by Imaginary Coherence Assessment.

We studied sex-related differences in gamma oscillation during an auditory oddball task, using magnetoencephalography and electroencephalography assessment of imaginary coherence (IC). We obtained a statistical source map of event-related desynchronization (ERD) / event-related synchronization (ERS), and compared females and males regarding ERD / ERS. Based on the results, we chose respectively seed regions for IC determinations in low (30-50 Hz), mid (50-100 Hz) and high gamma (100-150 Hz) bands. In males, ERD was increased in the left posterior cingulate cortex (CGp) at 500 ms in the low gamma band, and in the right caudal anterior cingulate cortex (cACC) at 125 ms in the mid-gamma band. ERS was increased in the left rostral anterior cingulate cortex (rACC) at 375 ms in the high gamma band. We chose the CGp, cACC and rACC as seeds, and examined IC between the seed and certain target regions using the IC map. IC changes depended on the height of the gamma frequency and the time window in the gamma band. Although IC in the mid and high gamma bands did not show sex-specific differences, IC at 30-50 Hz in males was increased between the left rACC and the frontal, orbitofrontal, inferior temporal and fusiform target regions. Increased IC in males suggested that males may acomplish the task constructively, analysingly, emotionally, and by perfoming analysis, and that information processing was more complicated in the cortico-cortical circuit. On the other hand, females showed few differences in IC. Females planned the task with general attention and economical well-balanced processing, which was explained by the higher overall functional cortical connectivity. CGp, cACC and rACC were involved in sex differences in information processing and were likely related to differences in neuroanatomy, hormones and neurotransmitter systems.

Improvement in treatment results of glioblastoma over the last three decades and beneficial factors.

BACKGROUND: The purpose of this study is to elucidate the trend of glioblastoma outcome and scrutinize the factors contributing to better outcome over three decades. METHODS: Survival time and the influencing factors were retrospectively analyzed in 223 newly diagnosed primary glioblastoma patients during 1980-2010. Appraised factors included age, sex, tumor site, year of surgery, extent of resections, use of surgery supporting system, Karnofsky Performance Status (KPS), chemotherapy, conventional external beam radiotherapy (EBRT), and CyberKnife stereotactic radiotherapy (CK-SRT) use. RESULTS: The median survival time (MST) in all patients was 13.6 months. The MSTs for 4 periods were 9.8 (1980-1990), 13.7 (1991-2000), 12.9 (2001-2005), and 15.8 months (2006-2010), respectively (p=0.0047). Total resection, subtotal resection, partial resection, and biopsy had MSTs of 31.8, 13.9, 11.4, and 7.0 months, respectively (p<0.0001). Regarding chemotherapy, MSTs of the temozolomide base group and nimustine hydrochloride (ACNU) base group were 16.9 and 14.6 months, respectively, whereas the MST of patients without chemotherapy was only 9.8 months (p<0.0001). The MSTs for 40-Gy EBRT plus CK-SRT and 60-Gy EBRT were 19.1 and 10.7 months, respectively (p<0.0001). But in sub-selected patients, treated during 2001-2010, whose resection rate was total resection or subtotal resection, EBRT was completed and postoperative KPS was greater than or equal to 70, the MST with and without CK-SRT was 26.6 and 18.3 months, respectively (p=0.1529). According to the Cox proportional hazards model, degree of resection, KPS, ACNU use, temozolomide use, bevacizumab use, EBRT dose, and CK-SRT use were good prognostic factors. Use of neuronavigation and use of intraoperative magnetic resonance imaging were related to higher resection rate, but not determined as prognostic factors. CONCLUSIONS: We observed a gradual improvement in glioblastoma outcome, presumably because of improvements in therapeutic modalities for surgery, anticancer agents, and radiation, but the efficacy of CK-SRT remains unclear.

MRI T2 hypointensity of metastatic brain tumors from gastric and colonic cancers.

BACKGROUND: Metastatic brain tumors from gastric and colon cancers are frequently revealed by hypointensity on T2-weighted magnetic resonance images (MRIs). However, the reason for this T2 hypointensity has yet to be clarified. We hypothesize that it is due to collagen deposition within the tissues. METHODS: Seven metastatic brain tumors, from 3 gastric cancers and 4 colon cancers were investigated. The degree of hypointensity of these tumors in T2-weighted images was quantitatively assessed as the ratio of gray-scale densities of tumor to brain using ImageJ. The result was compared with the amount of collagen in the resected specimens, which was quantified by ImageJ analysis software, utilizing the colour deconvolution method following Azan-Mallory staining. The degree of hypointensity was also compared with the ratio of viable epithelial component area/whole tissue area. Additionally, collagen distribution was studied by immunohistochemical staining. RESULTS: There was a clear negative correlation between intensity in T2-weighted images of these metastatic tumors and the amount of collagen they contained (R (2) = 0.766). However, there was no significant correlation between the T2 intensity and the ratio of viable epithelial component. Immunohistochemical analysis revealed that collagen types I, III, VII, X, and XI were expressed in the epithelial components and types IV, V, and VI were expressed in the stromal areas of the metastatic tumors. Collagen deposition was observed not only in stromal fibrous areas, but also in cytoplasmic areas in these metastatic tumors. CONCLUSIONS: Hypointensity of metastatic brain tumors arising from gastric and colonic cancers may be due to the accumulation of collagen in the tissues.

Subfrontal schwannoma mimicking neuroblastoma: case report.

Computed tomography (CT), performed in a healthy 28-year-old man after minor head injury, detected a frontal base tumor. Neurological examination revealed left hyposmia. On magnetic resonance imaging scans, there was a heterogeneously enhanced tumor located in the left paramedian frontal base with extension into the left ethmoid sinus. Angiography showed a hypervascular mass in the left anterior cranial fossa; it was mainly fed by the left ethmoidal artery. Positron emission tomography scanning showed moderate accumulation of 11-methylmethionine and low accumulation of 18-fluorodeoxyglucose (FDG) at the tumor site. Bone image CT disclosed compressive, nondestructive deformation of the left frontal base. The preoperative diagnosis was olfactory neuroblastoma or meningioma. The tumor was totally resected via bifrontal craniotomy. The tumor was histologically diagnosed as typical schwannoma; it was positive for S-100 protein. We report a rare subfrontal schwannoma with extension into the nasal cavity that mimicked neuroblastoma. Low FDG accumulation and compressive deformation of the anterior skull base may help in the differential diagnosis of these tumors.

Delayed radiation necrosis 7 years after gamma knife surgery for arteriovenous malformation--two case reports.

A 44-year-old woman and a 55-year-old woman were treated with gamma knife surgery (GKS) for occipital arteriovenous malformation (AVM). Angiography confirmed complete nidus obliterations 2 years after GKS. However, both patients complained of chronic headache and visual symptoms from around 7 years after GKS. Magnetic resonance imaging showed round masses with or without cystic change surrounded by large areas of brain edema. Angiography also showed complete obliteration of AVM at this time. Extended corticosteroid treatment failed to control the edema. Both patients underwent total surgical removal of the mass. Visual disturbance and chronic headache improved postoperatively and the brain edema rapidly subsided. The histological diagnosis was radiation necrosis in both cases, attributed to the low conformity index and large 12-Gy volume due to usage of a large collimator for GKS. These cases of delayed radiation necrosis after GKS suggest that surgical removal of necrotic lesions is necessary for radiation necrosis intractable to medical treatment.

Xanthogranuloma in the suprasellar region.

A 26-year-old man presented with a xanthogranuloma located exclusively in the suprasellar region manifesting as general fatigue, bitemporal hemianopsia, and polyuria. Endocrinological examination disclosed severe hypopituitarism. Magnetic resonance imaging demonstrated a clearly defined suprasellar mass that was heterogeneously enhanced after gadolinium administration and was markedly hypointense on T(2)-weighted images. The tumor was subtotally removed under a preoperative diagnosis of craniopharyngioma. Histological examination found fibrous tissue with abundant cholesterol clefts, multinucleated giant cells, and hemosiderin deposits, but no epithelial cells. Xanthogranulomas of the sellar region are reported to be predominantly located in the sella turcica, but should be included in the differential diagnosis even in cases of suprasellar mass lesions.