Lipoastrocytoma: Case report and review of the literature.

Lipoastrocytoma is an extremely rare tumor, with only six cases described. We report the case of an astrocytoma involving the upper part of the cerebellar-pontine angle and the right portion of the clivus starting from the brainstem with a diffuse lipomatous component in a 39 year-old man. The patient was admitted with headache of 1 year's duration and diplopia over the previous 3 months. MRI revealed a ponto-cerebellar lesion that showed irregular enhancement after contrast administration. Subtotal excision of the tumor was accomplished. Adjuvant chemotherapy and radiation therapy were not administered. Histologically the tumor showed the classical histology of low-grade astrocytoma and a portion of the lesion was composed of lipid-laden cells. Immunohistochemistry for glial fibrillary acid and S-100 proteins clearly demonstrated the glial nature of these cells. Ki-67/Mib-1 labeling index was low (2%). The patient remains in good neurological conditions after 10 months. Our case has a benign postoperative behavior, also after subtotal excision, with restrictions due to the short follow-up. It is important to record each new case of this rare tumor to produce a better characterization of this lesion.

Ruptured, dissecting posterior inferior cerebellar artery aneurysms: endovascular treatment without parent vessel occlusion.

INTRODUCTION: Treatment of a dissecting aneurysm of the medullary segments of the posterior inferior cerebellar artery (PICA) usually entails trapping of the diseased arterial segment with possible sacrifice of brainstem perforators. The goal of the work was to review our experience with selective coiling of ruptured, dissecting aneurysms of the anterolateral segments of the PICA without parent vessel occlusion. METHODS: Eleven consecutive patients (9 women, 2 men, mean age 47.2 years) were retrospectively reviewed from a prospectively acquired neuroradiological database. On admission three patients had Hunt and Hess (HH) grade I, three HH grade II, two HH grade III, and one HH grade IV. Outcome was evaluated according to the modified Rankin scale (mRS) score. Follow-up (mean:19.4 months) consisted of magnetic resonance angiography and/or digital subtraction angiography in ten patients. RESULTS: Ten patients had mRS score 0 and one mRS score 2. No treatment failure occurred. The aneurysm was completely occluded in seven patients, a neck residue was present in two, and a loose coil mesh was present in two. Recurrence occurred in three patients, and all were successfully retreated for a total of 13 procedures. Procedure-related complications were all without clinical consequences and included a coil perforation in one procedure and stagnant filling of the parent vessel in six procedures. PICA occlusion did not occur in any patient. CONCLUSION: Coiling of ruptured, isolated dissecting aneurysms of the PICA without parent vessel occlusion is feasible, relatively safe and effective in preventing early/medium-term rebleeding. A strict angiographic follow-up program is, however, necessary to detect recurrence.

Merlin expression in secretory meningiomas: evidence of an NF2-independent pathogenesis? Immunohistochemical study.

One of the most common chromosomal regions implicated in the meningiomas tumorigenesis is 22q12 where the neurofibromatosis 2 (NF2) gene resides. The NF2 tumor-suppressor gene encodes for the merlin/schwannomin protein, which is responsible for the inherited disease neurofibromatosis 2. NF2 gene mutations predominantly occur in transitional and fibroblastic meningiomas, whereas the meningothelial variant is less affected. Secretory meningioma is an infrequent meningioma subtype. Its most typical morphologic feature is the presence of intracytoplasmic or extracytoplasmic round hyaline, eosinophilic, and periodic acid Shiff-positive bodies in a lesion frequently otherwise classifiable as meningothelial meningioma. This study reviews the immunohistochemical merlin expression in 14 consecutive secretory meningiomas. Our purpose was to investigate if secretory meningiomas, analogous to meningothelial meningiomas, follow a molecular route of pathogenesis independent of the neurorofibromatosis 2 gene-associated pathway. All meningiomas showed positive immunocoloration involving the majority of the hyaline inclusions and secretory cells; in 12 (86%) meningiomas, a positive immunoreaction was also documented in nonsecretory tumoral cells. Our results may indicate a molecular, besides morphologic, similarity between secretory and meningothelial meningiomas: the almost constant merlin immunohistochemical expression in our series gives evidence for a possible NF2 gene-independent pathogenesis in secretory meningiomas.

Cyclooxygenase-2 (COX-2) overexpression in meningiomas: real time PCR and immunohistochemistry.

Cyclooxygenase-2 (COX-2) is the inducible form of the enzyme involved in the first steps of the prostaglandins and thromboxane synthesis. COX-2 up-regulation is demonstrated in tumors where it can modulate tumoral progression, metastasis, multidrug resistance, and angiogenesis. Experimental data suggest a possible therapeutic use of the COX-inhibitors nonsteroidal antiinflammatory drugs (NSAIDs). NSAIDs can block tumor growth through many mechanisms, especially through antiangiogenic and proapoptotic effects. Moreover, NSAIDs can also improve the efficacy of radiotherapy, chemotherapy, and hormonal therapy. This study reviews the COX-2 expression as evaluated through immunohistochemistry and real time polymerase chain reaction (RT-PCR) in 23 meningiomas [14 World Health Organization (WHO) grade I; 5 WHO grade II; 3 WHO grade III; 1 oncocytic meningioma]. At immunohistochemistry all the lesions but 4 (83%) were COX-2 positive. At RT-PCR 9 meningiomas, 8 WHO grade I and 1 WHO grade II, showed a COX-2 expression greater than the reference value (average expression of all meningiomas that we studied). The association between tumor grade and immunohistochemical or RT-PCR COX-2 expression was not significant (P=0.427 and P=0.251, respectively). In conclusion, even if further studies on larger series are necessary, the common COX-2 overexpression in meningiomas may suggest considering the COX-2 inhibitors, alone or in combination with radiotherapy, a potential area of therapeutic intervention in some selected meningiomas.

NF2 gene expression in sporadic meningiomas: relation to grades or histotypes real time-pCR study.

One of the most common regions involved in the meningiomas tumorigenesis is chromosome 22q where the NF2 gene resides. The deficiency or loss of the NF2 gene product, merlin/schwannomin, plays a role in tumor development and metastatization. Conflicting results have been reported on the prognostic value of merlin in meningiomas. Several studies have indicated NF2 gene inactivation as an early tumorigenic event unrelated to the histological grade or clinical behavior. On the contrary, the NF2 gene alteration rate differs between the different histotypes. A pathogenesis independent from the NF2 gene has been suggested in meningothelial meningiomas. In the present work, we studied the NF2 gene expression through real time-PCR (RT-PCR) in 30 meningiomas. The average of the NF2 gene expression of all meningiomas was considered as reference value. The average of expression of WHO grade I and II meningiomas was higher than the average of all meningiomas, whereas that of WHO grade III meningiomas was lower. When we compared the NF2 gene expression in the different meningioma grades we did not note a significant difference (P = 0.698) despite the tendency to decrease from grade I to grade III. The average expression of meningothelial meningiomas was higher than the reference value, and that of non-meningothelial meningiomas was lower. The difference in NF2 gene expression between meningothelial and non-meningothelial meningiomas was statistically significant (P = 0.013). Our data supports the finding that alterations in NF2 gene alteration are histotype related but not grade related.

Oncocytic meningiomas: Cases with benign histopathological features and a favorable clinical course.

OBJECT: Oncocytic meningioma has recently been recognized as a distinct morphological variant of intracranial meningothelial neoplasms, and only a few cases have been reported in the literature. The first description of this lesion, which was based on data in six cases, revealed a potentially aggressive nature with a tendency to infiltrate the brain and to recur. However, the true behavior of, and the long-term follow-up data for, such lesions must still be outlined. METHODS: The authors report on five cases of intracranial oncocytic meningiomas. On neuroimaging, the lesions showed the characteristic features of common meningiomas. All patients underwent gross-total removal of the mass together with the adjacent dura mater. No additional treatments were administered. Histologically, the tumors were composed of sheets, nests, and cords of large polygonal neoplastic cells with finely granular cytoplasm. Necrosis was absent in all cases. Mitosis was also absent or exceedingly rare, and no brain cortex infiltration was observed. The follow up ranged from 6 to 54 months (mean 32.4 months). At the last follow-up evaluation, all patients were asymptomatic and magnetic resonance imaging examinations demonstrated no evidence of tumor recurrence. CONCLUSIONS: Data in the presented cases did not confirm a previously described propensity to aggressiveness in this meningioma subtype. In fact, the histological features as well as the long-term favorable clinical course may suggest benign behavior of such neoplasms, as in the common forms of meningiomas.

Cyclooxygenase-2 in oligodendroglioma: possible prognostic significance.

Cyclooxygenase-2 (COX-2) is the inducible form of the enzyme involved in the first two steps of the prostaglandins and thromboxane synthesis. Up-regulation of COX-2 is demonstrated in tumors where it can modulate tumoral progression, metastasis, multidrug resistance and angiogenesis. Selective COX-2 inhibitors are seen with growing interest in the tumors treatment. This present study reviews the COX-2 expression in 32 primary oligodendrogliomas (24 WHO II; eight WHO III) and two glioblastomas with prominent oligodendroglial features (WHO IV). Immunohistochemical results were compared with survival in order to verify the COX-2 prognostic significance. COX-2 positivity was found in 44% tumors. Median survival of the patients with a COX-2 positive lesion was 37 months; median survival of the patients with a COX-2 negative lesion was 93 months (P =0.010). Twenty-nine percent WHO grade II tumors, 87% WHO grade III, 50% WHO grade IV resulted COX-2 positive (P =0.016). In patients affected by WHO grade II oligodendroglioma, median survival was 24 and 96 months, respectively, in COX-2 positive and negative lesions (P =0.012). In conclusion, even if further studies on different, homogeneous and larger series in vivo are certainly necessary, it is believed that COX-2 could really have a prognostic value and can be considered as a possible therapeutic opportunity.

Meningioma-primary brain lymphoma association.

The authors report a rare meningioma-primary cerebral B cell lymphoma association that occurred in an insulin-dependent type-I diabetic woman. The woman was initially operated on because of meningothelial meningioma of the fronto-basal region, and 2 months later showed a primitive-non-Hodgkin B cell lymphoma, localized in the same area as the meningioma. The published literature on the meningioma-primary cerebral lymphoma association is revised.

Plasma cell granuloma--an enigmatic lesion: description of an extensive intracranial case and review of the literature.

We present an unusual case of intracranial plasma cell granuloma in a 70-year-old man with a 6-month history of progressive visual disturbance. The lesion extensively involved the cranial base, extended into the frontal region, and reached the floor of the third ventricle in the suprasellar area. Microscopic examination of multiple diagnostic transsphenoidal biopsies showed an inflammatory proliferation with a predominance of cells that were immunohistochemically determined to be polyclonal plasma cells. Ultrastructural analysis confirmed the presence of numerous mature plasma cells in a mixed inflammatory proliferation. In situ hybridization for Epstein-Barr viral RNA revealed no evidence of viral expression. The patient was treated with steroid therapy and radiotherapy, without any appreciable reduction of the lesion's size. He is alive with persistent severe visual disturbance 14 months after the diagnosis. We discuss the etiopathogenetic, diagnostic, and therapeutic issues related to this entity, and review the literature.

Extraventricular neurocytoma: morphological and immunohistochemical considerations on differential diagnosis.

Neurocytoma is an unusual neuronal tumor especially affecting young people. It commonly arises in the ventricles and has a benign outcome. Herein, we report on a rare case of extraventricular neurocytomas (right parietal lobe) in a young girl admitted to hospital for a cranial trauma subsequent to a seizure. The tumor, radiologically well-circumscribed, cystic and enhancing, was surgically excised. The patient, who received no post surgical treatment, is alive and well after 18 months of follow-up. Pathological examination showed a well-differentiated lesion composed of uniform, round cells with perinuclear halos in a neuropil background and immunohistochemically positive for neuronal markers (synaptophysin, neuron-specific enolase, neurofilaments). The authors emphasize the role of the morphological and immunohistochemical evaluations to recognize this rare tumor.

Cerebral microarteriovenous malformations: diagnostic and therpeutic features in a series of patients.

BACKGROUND AND PURPOSE: Few collected series of cerebral microarteriovenous malformations (micro-AVMs) have been reported. Our propose was to assess the unique diagnostic and therapeutic challenges posed by these lesions and their influence on outcomes. METHODS: The clinical presentation, diagnostic features, principles of endovascular or surgical treatment, and outcomes for a consecutive series of 10 patients (five male, five female; mean age, 48.8 years; age range, 31-65 years) with angiographically demonstrated cerebral micro-AVMs were retrospectively analyzed. RESULTS: All patients presented with a cerebral hematoma (supratentorial in eight, infratentorial in two, intraventricular in one, subarachnoid in one; mean volume, 11.6 cm(3)), which was superficially situated in nine patients. Neurologic deficits were observed in nine patients, and three patients had seizures. The mean delay between the onset of symptoms and diagnosis was 129.8 days (range, 6 days to 1 year). Superselective angiography was performed in seven patients and followed by successful acrylic embolization of the lesion in five. Five patients underwent surgical intervention, which led to definitive resection. Although long-term neurologic problems were present in eight patients, they were able to return to their previous activities and employment. CONCLUSION: The diagnosis of cerebral micro-AVMs requires a high index of suspicion, especially in young adults with atypical hemorrhaging. Single-shot embolization of micro-AVMs may be a safe alternative to the established surgical therapy in select cases. Outcomes depend mostly on the clinical conditions at admission.

Oncocytic meningioma: a case report.

Oncocytic meningioma is a recently described rare variant of meningothelial neoplasms that typically occurs as a large cell tumor with granular cytoplasm. The distinct histological features of numerous cells with granular cytoplasm and the ultrastructural evidence of numerous mitochondria in the cytoplasm differentiate this tumor from other neoplasms with granular appearance. We report an additional case of oncocytic meningioma investigated by ultrastructural and immunohistochemical methods.