A case of atypical teratoid/rhabdoid tumor in the internal auditory canal.

OBJECTIVE: The case of a thirteen-year-old woman showing an atypical teratoid/rhabdoid tumor (AT/RT) primarily occurred in the internal auditory canal was presented. RESULTS: There was a delay in diagnosing AT/RT because of the first histological diagnosis of benign neurofibroma. If we had changed the surgical approach to one which was middle cranial fossa-based or translabyrinthine in the second or third operation, we might have reached an earlier final diagnosis. Although we faced a dilemma about whether to sacrifice facial nerve function for dissection of the tumor, we should have considered the possibility of malignancy at an earlier stage. CONCLUSION: This is a case report of AT/RT in the internal auditory canal presenting with progressive hearing loss as the initial symptom. Although no previous reports of AT/RT primarily occurring in the internal auditory canal are existent, this rare form of the disease should be considered in future evaluations as a differential diagnosis for internal auditory canal tumor.

Granulofilamentous meningioma.

A 55-year old female was referred to the Department of Neurosurgery, Kitasato Hospital, because of a hearing impairment. Neuroimaging revealed a typical meningioma attached to the falx in the right frontal region. During surgery, an encapsulated, circumscribed, reddish-gray, slightly hard tumor attached to the falx was completely removed by an interhemispheric approach. On light microscopy, many of the tumor cells contained eosinophilic inclusions with single or multiple vacuoles that displaced the cytoplasm. The nuclei of the tumor cells were eccentric. There were no signs of malignancy in the specimen. Electron microscopy revealed that most of the eosinophilic inclusions were composed of filaments measuring 12 nm in diameter. There have been several reports of benign meningiomas with eosinophilic inclusions composed of intermediate filaments. The microscopic differences between these types of tumor and rhabdoid meningiomas are very subtle, and it is important the two types of tumors are not confused. Benign meningiomas with eosinophilic inclusions comprising intermediate filaments, for example the tumor described in this report, have been diagnosed as granulofilamentous meningiomas, which is a subtype of benign meningioma.

Clinicopathological features of human brainstem gliomas.

We describe the clinicopathological features of 25 brainstem gliomas (BSGs). Twenty BSGs located in the pons and were all in children. Four BSGs located in the medulla oblongata were in 2 children and 2 adults. One (in a child) was located in the midbrain. Radiological findings on MR images were low-intensity on T1 weighted images and high-intensity on T2 weighted images. Mean survival when pontine glioma was treated by radiotherapy and/or use of temozolomide was 14 months, although 4 patients (3 cervicomedullary types and one focal type arising from midbrain) are alive. Follow up was from 5 months to 6 years. Histopathological features of 10 cases of the diffuse type were: 4 grade II astrocytomas, 4 grade III astrocytomas, and 2 glioblastomas. MIB-1 index was from 0.8 to 38 %. P53 was positive for 80 % of 15 tumors and there were no negative results. MGMT was positive in 60 % of 15 tumors and negative in 12.4 %. IDH1 was negative in 61.6 %. There was no positive result for IDH1 in this study. Thus, our histopathological results were indicative of high p53 immunoreactivity and no IDH1 immunoreactivity related to secondary malignant change.

Investigation of IgG4-positive cell infiltration in biopsy specimens from cases of hypertrophic pachymeningitis.

This study was an immunohistological study of IgG4-positive cell infiltration in 6 cases of hypertrophic pachymeningitis excluding secondary hypertrophic pachymeningitis caused by infectious diseases such as aspergillosis. The cases included 5 males and 1 female, ranging in age from 36 to 82 years (mean, 55 years). A biopsy was performed in all of the cases for diagnostic purposes, revealing fibrous dural hyperplasia with nonspecific inflammatory cell infiltration histologically. Two of the 6 patients had been treated with steroids before the biopsy, which was taken for poor response to steroid treatment. In these two cases, some IgG-positive cell infiltration of the thickened dura was observed; however, most of the cells were IgG4-negative. In the remaining four cases, many IgG- and IgG4-positive cells infiltrated the thickened dura and the IgG4-positive/IgG-positive cell ratio exceeded 40%. One of these patients was finally diagnosed with IgG4-related sclerosing disease, since he was diagnosed subsequently with retroperitoneal fibrosis. There was no evidence of any other lesions associated with IgG4-related sclerosing disease, other than in the dura. It is not rare for IgG4-positive cells to appear in the dura in cases of hypertrophic pachymeningitis; however, no IgG4-related systemic disease is present in these cases. Hypertrophic pachymeningitis with IgG4-positive cells may have some kind of relation to other systemic autoimmune diseases.

Two cases of nevoid basal cell carcinoma syndrome associated with meningioma caused by a PTCH1 or SUFU germline mutation.

Nevoid basal cell carcinoma syndrome (NBCCS) is an autosomal dominant disorder characterized by developmental defects and tumorigenesis. The gene responsible for NBCCS is PTCH1. The development of meningioma in NBCCS patients is a rare event. Here, we report two cases of NBCCS in which meningiomas did develop. The first patient carried a germline mutation in one allele of PTCH1, c.290dupA (p.N97KfsX43). In addition, the meningioma sample carried a somatic mutation, c.307delG (p.Val103LeufsX15), in the other allele of the same gene, suggesting a second hit. This is the first case of NBCCS-associated meningioma explained by the standard two-hit hypothesis. The second patient had a germline nonsense mutation in the SUFU gene, c.550C>T (p.Q184X). SUFU is located downstream of PTCH1 in the sonic hedgehog signaling pathway. This is the second time a germline mutation in SUFU has been found to cause NBCCS. Together with the previous report describing three cases of non-NBCCS medulloblastoma carrying a germline mutation in this gene, individuals with a SUFU germline mutation are expected to have a markedly high risk of developing medulloblastoma and probably meningioma.

Adult cerebellar glioblastoma cases have different characteristics from supratentorial glioblastoma.

This study is a histological and clinical investigation of four cases of cerebellar glioblastoma, a rare tumor. The cases included three males and one female, from 33 to 67 years in age (mean 49 years). Tumor resection, postoperative irradiation and chemotherapy were performed in all cases. Two patients died of local tumor recurrence after 14 and 27 months. Another patient relapsed after 10 months; however, after additional tumor resection and second line chemotherapy, she remains disease-free 41 months after the initial treatment. The fourth patient has not relapsed in the 6 months since initial treatment. The histopathology of all cases was glioblastoma with pseudopalisading necrosis. However, low-grade glioma histopathology was found in three patients. All glioblastomas were immunopositive for p53 and immunonegative for epidermal growth factor receptor (EGFR) and isocitrate dehydrogenase 1 (IDH1). These adult cerebellar glioblastoma cases had similar clinical and pathological characteristics, and had different characteristics compared with supratentorial glioblastomas.

Pilocytic astrocytoma with abundant oligodendroglioma-like component.

An 18-year-old girl presented with a history of visual disturbance without headache, nausea, or vomiting in May 2010. In July 2010, the patient visited our hospital because of visual disturbance. Head magnetic resonance images revealed hydrocephalus caused by a ring-enhancing mass lesion located in the vermis. Total tumor removal was performed. Histological findings revealed that honeycomb cells resembling oligodendrocytes accounted for most parts of the tumor. Rosenthal fibers and hyaline droplets were seen in a small portion. The tumor cells were immunoreactive for GFAP and Olig2, but none of the tumor cells were immunoreactive for Symaptophysin, EMA, or IDH 1. according to these findings, the tumor was diagnosed as pilocytic astrocytoma with an abundant oligodendroglioma-like component. Pilocytic astrocytoma is known to be associated with an oligodendroglioma-like component; however, the differential diagnosis for oligodendroglioma may be difficult when an oligodendroglioma-like component occupies most of the tumor.

Utility of intraoperative fluorescent diagnosis of residual hemangioblastoma using 5-aminolevulinic acid.

Hemangioblastoma is a benign tumor of the cerebellum, and treatment involves surgical excision, both as the initial treatment and also in case of recurrence. Recurrence of hemangioblastoma can be local due to incomplete resection or can be distant and separate from the tumor resection region. Local recurrence can largely be avoided by verifying for any residual tumor intraoperatively before closure. In this study, we used intraoperative fluorescent diagnosis using 5-aminolevulinic acid (5-ALA) to verify the presence of a residual tumor during surgical resection. Nine patients with hemangioblastoma were given 1 g of 5-ALA orally before surgery, and a laser beam of 405 nm was focused on the tumor during resective surgery. Fluorescence of protoporphyrin IX (PPIX) was observed in the core of tumor in all the cases. Fluorescence of PPIX was observed in the peritumoral cyst wall in two patients after tumor resection, and in both of them fluorescent parts of PPIX were resected and histological examination showed tumor cells. Usually, there are no tumor cells in the peritumoral cyst of a hemangioblastoma, yet hemangioblastomas may sometimes recur from an unresected cyst wall. It is thus necessary to excise an infiltrating cyst of tumor cells to prevent recurrence. Intraoperative fluorescent diagnosis using 5-ALA is a useful method to discern whether tumor cells are present in the peritumoral cyst wall of a hemangioblastoma.

Epstein-Barr virus (EBV)-associated primary central nervous system lymphoma: is incidence of EBV expression associated with median survival time?

The frequency and clinical features of Epstein-Barr virus (EBV)-associated primary central nervous system lymphoma (PCNSL) in elderly patients were investigated in this study. Thirty-three PCNSL cases were enrolled in the retrospective study. Biopsies were performed, and tissue was embedded in paraffin and sectioned. In-situ hybridization of EBV-encoded small RNAs was then conducted. Specimens were scored as having one of three possible results: negative (no EBV-positive cells), slightly positive (<50% EBV-positive cells), and strongly positive (>50% EBV-positive cells). Fifteen cases were negative for EBV expression. Sixteen cases were slightly positive, and two cases (68 and 79 years of age) were strongly positive. The incidence of strongly positive EBV expression in PCNSL was 6.1%. The incidence of strongly positive EBV expression in PCNSL patients ≥65 years of age was 13%. Median survival time differed significantly among PCNSL patients treated with high-dose methotrexate and radiotherapy. Importantly, the strongly EBV-positive PCNSL cases had the worst outcomes, and the EBV-negative PCNSL cases had the best outcomes. These results suggest that EBV infection may affect the treatment outcome of PCNSL. In the future, examination of EBV expression in PCNSL patients who receive individualized treatment may be useful.

Subependymal giant cell astrocytoma with oncocytic change.

A 49-year-old woman presented with a history of periodic episodes of nausea and vomiting starting in 2006. In June 2009, the patient lost consciousness and was transported to our hospital. Head computed tomography (CT) revealed hydrocephalus caused by an enhancing mass lesion with calcification located in the right lateral ventricle around the foramen of Monro. Total tumor removal was performed. Histologic findings revealed fibrillated spindle tumor cells and giant tumor cells with abundant cytoplasm. The spindle tumor cells were immunoreactive for GFAP and S-100 protein, but none of the giant tumor cells were immunoreactive for GFAP or S-100 protein. Electron microscopic examination revealed abundant mitochondria in the tumor cell cytoplasm. According to these findings, this tumor was diagnosed as subependymal giant cell astrocytoma (SEGA) with oncocytic change, which is extremely rare.

Dural arteriovenous fistulas in the cavernous sinus: clinical research and treatment.

Introduction. The purpose of this paper is to clarify the clinical course, with the dural carotid cavernous fistula (CCF), featuring a pallet of symptoms, paying special attention to radiological findings. Methods. Seventy-six consecutive patients with dural CCFs were investigated in detail, all of whom were defined by angiography. Results. The most common initial symptom was diplopia in 47 patients (62%) and the most frequently observed on arrival were type II, featuring cranial nerve palsies followed by the classical triad in 27, and then type I only with cranial nerve palsies. The time until admission with type I (mean: 6.7 W ± 6.0) was significantly shorter than that with type II (mean: 25.1 W ± 23.5). Branches from bilateral carotid arteries widely inflowing into bilateral carotid cavernous sinus were present in 30 (39%), 20 (26%) of which also demonstrated direct inflow into the intercavernous sinus. type I and II had more multiple venous drainage routes as compared with type III (classical triad only on arrival) and IV (initial development of the classical triad followed by cranial nerve palsy). Conclusion. In our series of dural CCF patients, the most common initial symptom was cranial nerve palsy, mostly featuring multiple venous drainage including cortical drainage. Such palsies should be added to the classical triad as indicative symptoms. Bilateral carotid arteries often inflow into cavernous and intercavernous sinuses, which should be taken into account in choice of therapeutic strategy.