Manas Panigrahi

Activation of Wnt/β-catenin/Tcf signaling pathway in human astrocytomas

Astrocytomas are the most common form of primary brain tumors. Understanding the molecular basis of development and progression of astrocytomas is required to develop more effective therapies. Although, over activation of Wnt/beta-catenin/Tcf pathway is a hallmark of several forms of cancer, little is known about its role in human astrocytomas. Here, we report the evidence that Wnt/beta-catenin/Tcf signaling pathway is constitutively activated in astrocytic tumors. In the present study, human astrocytic tumors with different clinical grades were analyzed for mRNA expression of Dvl-1, Dvl-2, Dvl-3, beta-catenin, c-myc and cyclin D1 and protein levels of beta-catenin, Lef1, Tcf4, c-Myc, N-Myc, c-jun and cyclin D1. RT-PCR analysis demonstrated the overexpression of Dvl-3, beta-catenin, c-myc and cyclin D1 in astrocytomas. Western blotting revealed upregulation of beta-catenin, Lef1, Tcf4 and their target proteins in the core tumor tissues in comparison to peritumor and normal brain tissues. The protein and mRNA levels were positively correlated with the histological malignancy. Cytoplasmic and nuclear accumulation of beta-catenin, nuclear localization of Lef1, Tcf4, c-Myc, N-Myc, c-jun and cyclin D1 were demonstrated by immunohistochemical staining. Our studies tend to suggest that Wnt/beta-catenin/Tcf signaling pathway is implicated in malignancy of astrocytomas.

Pathology of fungal infections of the central nervous system: 17 years' experience from Southern India

Aims:  To describe the pathology of central nervous system (CNS) fungal infections with particular reference to India.

Fungal rhinosinusitis: a clinicopathological study from South India

Fungal rhinosinusitis (FRS) is uncommon and accounts for 6–12% of culture or histologically proven chronic sinusitis. FRS may be acute or chronic. The aim of this paper was to study the histological features that contribute to the diagnosis and sub typing of FRS, using a retrospective review of all paranasal sinus mucosal biopsies from January 2005 to December 2008. The clinical features, predisposing conditions, imaging findings, and extent of the lesion were noted. The slides were reviewed with hematoxylin and eosin, Gomori’s methenamine silver, and periodic acid Schiff stains. Culture reports were obtained wherever material was subjected to culture. There were 63 biopsies diagnosed as FRS (45.7%) out of 138 biopsies of chronic sinusitis in the study period. The FRS was classified as allergic in 15 (23.8%), chronic non-invasive (sinus mycetoma) in 1 (1.6%), chronic invasive in 10 (15.87%), granulomatous invasive in 19 (30%), and acute fulminant in 18 (28.5%) biopsies or surgical resections. Predisposing conditions were identified in 19 patients with diabetes mellitus as the commonest. Seventeen of the 18 patients with acute fulminant FRS had predisposing conditions. As per the results, the characteristic histological features were allergic mucin in allergic, fungal ball in chronic non-invasive, sparse inflammation and numerous hyphae in chronic invasive, non caseating granulomas with dense fibrosis in granulomatous invasive, and infarction with suppuration in acute fulminant FRS. Aspergillus sp. was the commonest etiologic agent. To conclude, predisposing risk factors were more common in invasive FRS than in non-invasive sinusitis and Aspergillus species was the most common etiologic agent.

Wnt/β-catenin/Tcf Signaling Pathway Activation in Malignant Progression of Rat Gliomas Induced by Transplacental N-Ethyl-N-Nitrosourea Exposure

Although Wnt/β-catenin/Tcf signaling pathway has been shown to be a crucial factor in the development of many cancers, little is known about its role in glioma malignancy. In the present study, we report the first evidence that Wnt/β-catenin/Tcf signaling pathway is constitutively activated in experimental gliomas induced by single transplacental dose of N-ethyl-N-nitrosourea (ENU). In the present study we analyzed ENU induced rat gliomas of different stages (P90, P135 and P180) for the expression of β-catenin, Lef1, Tcf4 and their targets c-Myc, N-Myc and cyclin D1. Western blot analysis revealed upregulation of β-catenin, Lef1, Tcf4, c-Myc, N-Myc and cyclin D1 in gliomas compared to controls and their levels were progressively increased from initial stage (P90) to progression stage (P180). In consistent with this, immunohistochemistry revealed the cytoplasmic and nuclear accumulation of β-catenin, and nuclear positivity was evident for Lef1, Tcf4, c-Myc, N-Myc and cyclin D1. Based on these results, we conclude that Wnt/β-catenin pathway may play a major role in the tumorigenesis and tumor progression in ENU induced rat gliomas.

A 10-year retrospective study of hemangioblastomas of the central nervous system with reference to von Hippel–Lindau (VHL) disease

We aimed to analyze the clinical, radiological, surgicopathological and clinical outcome data of patients who underwent surgery for central nervous system (CNS) hemangioblastoma (HBL) with or without von Hippel-Lindau (VHL) disease. The clinico pathological and radiological findings, management and clinical outcome of patients with CNS HBL (operated between 2000 and 2009) were analyzed retrospectively. The differences between sporadic and VHL-associated HBL were analyzed. Forty-nine patients (28 male, 21 female) underwent surgery for CNS hemangioblastoma. Thirty-nine patients (80%) harbored sporadic HBL whereas 10 (20%) had VHL disease. The mean age at diagnosis for VHL-associated HBL was 32 years when compared to 40 years in sporadic HBL. The lesions were solitary in 41 patients and multiple in eight. The cerebellum was the most common site of HBL (35/49, 71%). Six patients with sporadic and two with VHL disease had spinal lesions. On imaging (available in 43/49 patients), a cyst with a mural nodule was the most common finding, seen in 16 patients (37.2%) whereas nine patients (21%) had solid and cystic lesions. Clinical presentation, radiological features, and histomorphology of HBL with or without VHL disease were similar. Multiple cysts in the pancreas, kidney, broad ligament, epididymis, clear cell renal cell carcinoma, phaeochromocytoma and retinal angiomas were the visceral manifestations seen in patients with VHL disease. Of all patients with VHL disease, three required multiple surgeries for new lesions and one died of renal failure and sepsis. Among the patients with sporadic disease (31/39), two died of surgical complications, one died of postoperative sepsis, three were lost to follow-up and the remainder had resolution of symptoms at 1year following surgery. We concluded that the diagnosis of VHL disease is important as management is more difficult and lifelong follow-up and counseling are required in these patients and for their at-risk relatives.

A clinicopathological and immunohistochemical study of central nervous system hemangiopericytomas.

Hemangiopericytomas (HPC) of the central nervous system (CNS) are uncommon dural-based tumors that mimic meningiomas clinically and radiologically. Because there are few reports about these tumors from India, we aimed to study the clinico-pathological and immunohistochemical features of CNS HPC. During 2000 to 2008 all 23 patients diagnosed with HPC of CNS at our Institution were reviewed in the study (11 males and 12 females, mean age of 46 years). Clinical, radiological and histopathological features were reviewed. There were 14 patients with grade II and nine with grade III tumors. Immunohistochemistry with antibodies to epithelial membrane antigen (EMA), vimentin, S-100, CD34 and Ki-67 was done on routinely processed, paraffin-embedded sections of 20 tumors. All patients were EMA and S-100 negative, and vimentin positive. CD34 was positive in only five out of 20 patients. The mean Ki-67 labeling index was 4.25% in grade II tumors and 7.8% in grade III tumors. We concluded that HPC are distinct from meningiomas in morphology, immunohistochemistry and biologic behavior, although they resemble each other clinically and radiologically, HPCs need to be differentiated from meningiomas.

Outcome of epilepsy surgery in children after evaluation with non-invasive protocol

OBJECTIVE To assess outcome of epilepsy surgery in children with medically refractory partial epilepsy evaluated with non-invasive protocol and to determine the predictors of outcome. PATIENTS AND METHODS Retrospective analysis of presurgical, surgical, and postsurgical data was performed in 87 children who had at least 1 year post surgery follow-up. Outcome was assessed according to Engels outcome classification. Stepwise regression followed by logistic regression analysis was employed in data analysis. RESULTS Mean follow-up was 32 (12-58) months and 44 (50.6%) were males. The age of onset of epilepsy was below the age of 2 years in 24 (30.8%). Resective surgery was done in 78 children. The commonest surgery performed was a temporal resection (88.9%) in adolescents and an extra-temporal resection ( 60.6%) in children. The commonest pathology was hippocampal sclerosis (HS) in adolescents and developmental, tumoral lesions, and gliosis in children. At last follow-up, 50 (64.1%) were seizure free and Engels favourable outcome was noted in 59 (75.6%). After stepwise regression analysis, variables found to be significant (P < 0.05) and predicting a favourable outcome were lesion on MRI, normal IQ, and partial seizures without secondary generalization. Bilateral spikes on interictal EEG and acute postoperative seizures were predictors of poor outcome. A regression model was developed; the sensitivity, specificity, accuracy, and area under ROC curve were 82%, 91%, 88.5%, and 0.97%, respectively. CONCLUSION Favourable outcome after epilepsy surgery can be obtained in children with temporal lobe epilepsy with HS and lesion-related epilepsies in developing countries with limited resources, after evaluation with a non-invasive protocol.

Intraoperative cytology (squash smear) in neurosurgical practice – pitfalls in diagnosis experience based on 3057 samples from a single institution

Objectives:  The smear technique is challenging for a neuropathologist where rapid and accurate diagnosis is to be given on small biopsies. The present study, a large retrospective analysis of squash smears in neurosurgical practice, was conducted to assess the usefulness, accuracy and the diagnostic pitfalls of smear diagnosis.

Teratomas in central nervous system: a clinico-morphological study with review of literature.

BACKGROUND Cranio-spinal axis teratomas are rare. This subset is interesting because symptoms can be varied, depending on the location. Histopathology is diagnostic; most of the lesions are benign. Rarely, malignancy develops in any of the somatic components. AIMS To study the demographic, clinico-morphological and follow-up data of central nervous system (CNS) teratomas. MATERIALS AND METHODS Cases diagnosed as mature or immature teratomas in the CNS over a 20-year period were included in the study. Clinico-radiological, demographic and follow-up data of these cases were analyzed. RESULTS A total of 14 tumors were diagnosed as teratomas. Of these, 11 were mature cystic teratomas; and 1 case each, of teratoma with malignant transformation, terato-carcinoma and mixed germ cell tumor (immature teratoma with germinoma). Six of the 14 cases were intracranial and 8 were spinal. Presenting features varied according to the location. Radiologically, contrast enhancement with predominantly solid component was suggestive of malignancy or an aggressive tumor. Morphologically, a variety of tissue derivatives were seen in the cases. Excision was curative or provided symptomatic relief in most cases; terato-carcinoma and mixed germ cell tumor patients needed adjuvant radiotherapy. CONCLUSION CNS teratomas are rare. Morphology and location decide outcome.

Comparative status of activated ERK1/2 and PARP cleavage in human gliomas

Gliomas are the most common form of cerebral tumors. Understanding molecular features of glioma will eventually allow for targeted intervention and more promising approaches for treating gliomas. The present study is therefore carried out to check the levels of activated ERK1/2 with respect to phospho‐tyrosine and cleavage of poly ADP‐ribose polymerase (PARP). Recent experiments support  that  extracellular  signal  regulated  kinase (ERK), a mitogen activated protein (MAP) kinase might have a critical role in cell proliferation. PARP is a DNA‐repair enzyme activated by DNA strand breaks. Overactivation of PARP after cellular insult lead to cell death caused by rapid depletion of cellular ATP. Three glioblastoma multiforme (GBM) and two astrocytoma biopsies (core tumor) and peripheral tissues were analyzed for the expression of p‐ERK1/2 and PARP. Results indicate higher p‐ERK1/2 in GBM. Cleaved fragments of PARP (89 kDa) were found to be more in core tumor tissue samples as compared to peripheral tumor tissues of both astrocytoma and GBM.