Correlation of expression pattern of aquaporin-1 in primary central nervous system tumors with tumor type, grade, proliferation, microvessel density, contrast-enhancement and perilesional edema.

OBJECTIVES: Brain edema, a hallmark of malignant brain tumors, continues to be a major cause of mortality. The underlying molecular mechanisms are poorly understood and thought to be mediated through membrane water-channels: aquaporins (AQP1,4,9). The abnormal upregulation of AQP1 in certain glial neoplasms has suggested a potential role in tumor pathogenesis, apart from being a novel target for newer therapeutic regimen. This study was undertaken to evaluate the expression of AQP1 in primary CNS tumors of various histologic types and grades, and its correlation with contrast-enhancement, perilesional edema, histomorphology, proliferation index and microvessel density. MATERIALS AND METHODS: Biopsy tissues from 30 patients (10 each from gliomas, meningiomas and other primary CNS tumors) were studied. Autopsy brain sections served as control. AQP1-immunoreactivity was correlated with histomorphology, radiology, proliferation index and microvessel density (MVD). RESULTS: AQP1 expression was increased in gliomas and ependymal tumors as compared to meningiomas. Intratumoral expression was homogenous in high-grade and membranous in low-grade neoplasms, while peritumoral areas showed expression around vessels and reactive astrocytes. High-grade tumors showed peritumoral upregulation, while low-grade had intense intratumoral expression. A trend of positive correlation was observed between AQP1-immunopositivity and increasing grade, higher MIB-1LI, increasing contrast-enhancement and more perilesional edema, and elevated MVD with raised AQP1:MVD ratio. CONCLUSIONS: AQP1-immunoexpression had a good correlation with high-grade tumors. AQP-upregulation in perilesional areas of high-grade tumors suggests its role in vasogenic edema. Further studies involving other AQP molecules, vascular endothelial growth factor (VEGF) and hypoxia inducible factor-1 α (HIF-1α) should be undertaken to evaluate its possible role as a potential surrogate marker of high-grade tumors heralding poor outcome, inhibition of which may serve as the basis for future targeted therapy.

Transciliary supraorbital keyhole approach in the management of aneurysms of anterior circulation: Operative nuances.

BACKGROUND: With improvement in neuroimaging, instrumentation and operative microscope optics, and with better understanding of microneuroanatomy, it is now possible to approach intracranial aneurysms of anterior circulation through a small eyebrow incision. AIM: The objective of the study is to highlight the advantages and limitations of transciliary supraorbital keyhole craniotomy for clipping of these aneurysms. MATERIALS AND METHODS: We present our experience with 55 intracranial aneurysms in the anterior circulation in 52 consecutive patients (23 females and 29 males, age range 22-70 years) operated between 2003 and 2009. All these aneurysms were clipped by a supraorbital transciliary incision and a craniotomy measuring 2.5 x 1.5 cm. One patient required bilateral keyhole craniotomies for bilateral aneurysms. RESULTS: Of the 52 patients, 37 patients were in Grade I/II, and the rest were in Grade III-IV. Clipping could be done in all the patients, and in twelve patients there was intraoperative rupture of the aneurysm. While there was a learning curve, no limitations were apparent, and none of the patients required revision of the procedure or wrapping. None of the patients had suboptimal clip application. Postoperative check angiogram showed obliteration of the aneurysm in all the patients. Patients with preoperative Grade I/II could be discharged from the hospital within seven days, and cosmetic result was excellent in all the patients. Four patients with preoperative Grade IV died in the postoperative period due to vasospasm. CONCLUSION: The transciliary supraorbital approach offers clipping of intracranial aneurysm in anterior circulation with low approach related morbidity as compared to standard approach.

Pituitary metastasis from medullary carcinoma of thyroid: case report and review of literature.

Pituitary is a rare site for metastases from thyroid cancer. Most reported cases have been of papillary and follicular carcinoma. Metastases from medullary thyroid carcinoma have not been reported. We report a case of intrapituitary metastasis from medullary carcinoma thyroid in a 38-year-old male, who had been operated for pituitary adenoma 5 years earlier. At the time of presentation in Nov 2006, he had visual field defects and a painless thyroid nodule. Further evaluation revealed medullary carcinoma thyroid, cervical and mediastinal lymphadenopathy, elevated serum calcitonin levels, and lobulated pituitary tumor. After surgical excision of thyroid and lymph node clearance, he underwent craniotomy and subfrontal excision of pituitary tumor. All the tumors were of identical histology, i.e., medullary carcinoma thyroid. Pituitary tumor was positive for calcitonin.

Clival pituitary adenoma with acromegaly: case report and review of literature.

The pituitary develops as a result of complex, intricate, and precise neuro-embryological events in the sixth to eighth weeks of gestation. Some ectopic cell rests can become adenomatous. Rarely, these cell rests in the clivus can be the site of formation of adenoma. Our patient, a 35-year-old parous woman, was being treated for acromegaly, and imaging studies revealed a clival mass lesion. Trans-sphenoidal excision was done and immunohistochemistry revealed the tumor to be a growth hormone-secreting tumor.

Intraventricular meningiomas: a clinicopathological study and review.

OBJECT: Intraventricular meningiomas are rare tumors. The origin of these tumors can be traced to embryological invagination of arachnoid cells into the choroid plexus. The authors analyzed data that they had collected to study the clinicopathological aspects and review the origin, presentation, imaging, and management of these tumors. METHODS: In this retrospective analysis, the authors describe the cases of 12 patients who had received a diagnosis of intraventricular meningioma and underwent surgery for the tumors. Nine of these patients were men and three were women. Features of neurofibromatosis Type 2 were present in two of the women. Nine of the tumors were located in the lateral ventricles, one was in the third ventricle, and two were in the fourth ventricle. Raised intracranial pressure (ICP) was the universal presentation in all the patients, and the preoperative diagnoses were confirmed on neuroimaging studies. Excision was performed using the parietooccipital (trigonal) approach for lateral ventricle tumors, the transcortical-transventricular route for the third ventricle tumor, and suboccipital craniectomy for fourth ventricle tumors. Postoperatively, one patient died and the others experienced resolution of their symptoms. Histopathological features of these tumors were similar to those seen in meningiomas in other locations. CONCLUSIONS: Intraventricular meningiomas are slow-growing tumors that become large prior to detection. Although they are commonly seen in the lateral ventricles, they occur in the third and fourth ventricles as well. Presentation is in the form of raised ICP with no localizing features; therefore the diagnosis is based on imaging studies. Hydrocephalus occurs due to obstruction of cerebrospinal fluid pathways. Excision requires planning to avoid eloquent cortex incision. The histopathological features are varied, although most of the tumors in the study were angiomatous meningiomas. These tumors are no different histologically from tumors that are dural in origin. No recurrence has been reported.