Management of Isolated Musculocutaneous Injury: Comparing Double Fascicular Nerve Transfer With Conventional Nerve Grafting.

PURPOSE: To compare the functional outcomes of nerve grafts and nerve transfers in the management of isolated musculocutaneous nerve (MCN) injuries. METHODS: We performed a retrospective case-control study of isolated MCN injury managed at a tertiary care center. The study group was composed of 12 patients managed with double nerve transfer whereas the 8 patients in the grafted group constituted the control group. RESULTS: In the study group, stab and missile injuries constituted most cases with a denervation period ranging between 3 and 9 months. Eleven patients in this group experienced a full range of active elbow flexion whereas one had antigravity flexion of 120°. Electromyography revealed the first sign of reinnervation of biceps at 10 ± 2 weeks, compared with 20 ± 2 weeks in the grafted group. The overall trend was for patients in the study group to have earlier return of active elbow flexion and better restoration of elbow flexion strength and range of (presumably active) elbow motion than those treated with grafting, although none of these measures reached statistical significance. CONCLUSIONS: We found that distal nerve transfer was a superior method of managing isolated MCN injury compared with conventional nerve grafting.

Morphometric study of nuclei and microvessels in gliomas and its correlation with grades.

INTRODUCTION: Modifications of nuclear morphology in conjunction with alteration in microvascular configuration are essential features encountered during the progression of glial tumors. In order to gain more insight into tumor biology of gliomas, objectives of the study were selected (a) to correlate morphometrically evaluated nuclear parameters [nuclear area (NA), nuclear perimeter (NP), nuclear density (ND), percentage of total nuclear area (%TNA)] and microvessel parameters [microvessel density (MVD), microvessel caliber (VC), microvessel cross sectional area (VCSA), total microvessel boundary density (TVBD), percentage of total VCSA (%TVCSA)] with WHO grading; (b) extend such correlations to the ratio parameters: ratio of MVD to ND (MDV/ND), ratio of TVBD to %TNA (TVBD/%TNA) and ratio of %TVCSA to %TNA (%TVCSA/%TNA); and (c) to correlate microvessel and ratio parameters with NP and ND. MATERIALS AND METHODS: A total of thirty gliomas managed at this institute during 2009-2012 were evaluated for various nuclear and microvessel parameters by image morphometry using a computerized digital photomicrograph system. For assessment of microvessel parameters CD34-immunostained sections were used while nuclear morphometry was performed on routine hematoxylin-eosin-stained sections. Appropriate statistical analysis was performed in correlation studies. RESULTS: All nuclear morphometric parameters showed strong positive correlation with tumor grades (r>0.7). In contrast, though all microvessel parameters exhibited positive correlation with grades, the parameters TVBD and %TVCSA showed strong positive correlation. The ratio parameters (MVD/ND) and (TVBD/%TNA) showed negative correlation with grades, whereas (%TVCSA/%TNA) did not exhibit meaningful correlation with grades. Further, while all microvessel parameters showed positive correlation with NP and ND; ratio parameters showed negative correlation with them. CONCLUSION: This study indicates that the parameters related to tumor growth (NA, NP, ND, %TNA), and angiogenesis showed increasing trend with tumor grades simultaneously; whereas the parameters related to supply of nutrients per nucleus showed decreasing trends with tumor grades, nuclear size and nuclear density. Thus, the former accounts for increased cellularity, mitosis, and vascular proliferation, while the latter culminates in tumor necrosis, all of which are essential components for grading of gliomas. The present study will therefore have a vital role as surrogate markers of grading of tumor.

Gross Appearance of Fine Needle Aspiration Smears: Can Adequacy of the Sample be Assessed and Correlated with their Microscopic Cytological Yield.

Background: Fine needle aspiration cytology (FNAC) is a simple procedure that is widely accepted as a first-line investigation. It should ideally be performed near the patient with microscopic assessment for evaluation of adequacy of aspirate. Since this is not always possible, a worthwhile substitute is to assess the gross appearance of the material obtained. This study was aimed to determine the value of this alternative rapid, bed-side approach. Method: This study was carried out in a tertiary care hospital for a duration of 1 year, where 50 cases undergoing FNAC in the out-patient department (OPD) were included. Unstained smears of commonly encountered lesions were photographed and assessed by three independent observers, who graded them into four grades, viz. Grade 1: unlikely to contain diagnostic material. Grade 2: possibly contains diagnostic material. Grade 3: probably contains diagnostic material. Grade 4: material suggesting a specific diagnosis. Results were subsequently compared with the microscopic findings of stained smears. Results: Distribution of the 50 cases between grades 1, 2, 3, and 4 were 5, 6, 17, and 22, respectively. Conclusion: Gross appearances of FNA smears are helpful in predicting the adequacy of the sample and sometimes the final microscopic diagnosis. The cellularity of a sample can be gauged by inspection and sometimes a likely diagnosis can be made. Some lesions show typical gross appearance easily detected by the experienced eye so a likely diagnosis can be predicted prior to microscopic examination. However, near-patient microscopic assessment of FNA specimens for rapid onsite evaluation, if available, should be the preferred mode.

Posterior approach for both spinal accessory nerve to suprascapular nerve and triceps branch to axillary nerve for upper plexus injuries.

Restoration of stability and movements at the shoulder joint are the 2 most important goals in the management of brachial plexus injuries. The 2 nerves that are preferentially targeted for this purpose are the suprascapular (SSN) and the axillary (AXN) nerves. These nerve transfers have conventionally been performed by the anterior approach, but recently transfers performed by posterior incisions have been gaining popularity, by virtue of being selective and located close to the target muscles. Herein, we describe the technical details of spinal accessory nerve (SAN) to SSN and triceps branch to AXN for upper plexus injuries, both performed by the posterior approach.

Correlation of histomorphologic prognostic markers and proliferative index with loss of heterozygosity 1p/19q and MGMT status in diffusely infiltrating gliomas.

BACKGROUND: Loss of heterozygosity (LOH)1p/19q, and epigenetic silencing of O(6)-methylguanine-DNAmethyltransferase (MGMT) gene, displayed promising role as predictive and prognostic markers in brain tumours. The present study correlated both with conventional histomorphologic prognostic markers and proliferative index in diffusely infiltrating gliomas (DIG). METHODS: Tissues from 45 patients were evaluated for LOH1p/19q using polymerase chain reaction based microsatellite analysis; and for MGMT using immunohistochemistry. Results were correlated with age, histologic type, WHO grade, and proliferation index. RESULTS: Mean MIB-1 LI showed significant correlation with tumour grade. MGMT-staining in grade II and IV tumours were 31.1% and 16.8%, respectively, while in DA and GBM it was 88.2% and 19.0%, respectively, which were statistically significant. Sixteen cases showed LOH 1p and/or 19q of which 10 (5 oligodendroglial, 3 GBM, AA, DA) had combined LOH; while three each showed 1p (all GBM) and 19q (2 DA and GBM) loss. In the MIB-1LI ≤ 5% and >5% groups LOH 1p and/or 19q was encountered in 6 and 10 cases, respectively. A significant inverse association was noted between LOH with MGMT. CONCLUSIONS: LOH1p/19q and MGMT shows good correlation with conventional histomorphologic and proliferation markers, and should constitute part of the optimal diagnostic workup of DIG.

Morphometric study of microvessels in primary CNS tumors and its correlation with tumor types and grade.

INTRODUCTION: Alterations of microvasculature are integral to CNS neoplasia, and a diagnostic feature of high-grade gliomas. The objectives of this study were two fold: First, to correlate morphometrically measured microvessel density (MVD), microvessel caliber (VC), and percentage of total microvessel area (%TVA) with WHO histologic grade in various types of primary CNS tumors. Second, to evaluate if such a correlation could be further refined by using mathematical derivatives of measured parameters namely coefficient of variation of VC (COofVC), microvessel cross-sectional area (VCSA), and percentage of total VCSA (%TVCSA). MATERIALS AND METHODS: Various microvessel parameters were assessed in a variety of 30 primary CNS tumors as consecutively encountered in routine surgical pathology practice including gliomas, meningiomas and others by image morphometry using CD34-immunostained sections. We introduced a novel method of effectively determining VC. Results were correlated with tumor type and grade. Appropriate statistical analysis was performed. RESULTS: Microvessel characteristics, especially VC (p<0.0022), VCSA (p<0.0164), CVofVC (p<0.0001), %TVCSA (p<0.0002) and %TVA (p<0.0003) of tumors were significantly greater than normal tissue. MVD increased in all tumors, excepting meningiomas, and was significantly higher in gliomas (p<0.0062). MVD showed negative correlation with VC (r=-0.808) and VCSA (r=-0.848) in the normal brain but was less significant in tumors. Unlike tumors, caliber distribution of microvessels in normal brain was noted to follow a Gaussian pattern. Histological grades of tumors showed positive correlation with MVD (r=0.547), VC (r=0.606), CVofVC (r=0.623), VCSA (r=0.485), %TVCSA (r=0.783) and %TVA (r=0.603). Calculated scores, estimated from multiple regressions of vessel parameters, correlated well with histological grade, with S2 (calculated using all measured as well as mathematically derived microvessel parameters) being better than S1 (calculated using measured parameters: MVD and VC). CONCLUSION: Tumor grades positively correlated with all microvessel parameters, with %TVCSA displaying the best. The correlation of %TVA with tumor grade was weaker than %TVCSA mainly due to the impact of MVD. These findings emphasize the value of VC as effectively measured using our novel method and best illustrated by its derivative %TVCSA (an indicator of blood flow), in addition to the well-recognized value of MVD in tumor prognostication. Multiple regressions of microvessel parameters provided the best correlation with grade. Morphometric analysis of microvessels in CNS tumor facilitates a better understanding of the tumor grade, tumor progression and overall prognosis.

Atypical MYC rearrangement pattern of 3' deletion and 5' amplification along with independent IGH rearrangement: A case study.

A spectrum of Cellular homolog of the v-myc oncogene (cMYC) alterations such as translocation, overexpression, mutation, and amplification plays an important role in lymphomagenesis, particularly in high-grade lymphomas, and are associated with prognostic significance. Accurate identification of cMYC gene alteration is important for diagnostic, prognostic, and therapeutic implications. With the application of different FISH (fluorescence in situ hybridization) probes that helped overcome the analytical diagnostic challenges as a result of variant patterns, we report rare, concomitant, and independent gene alterations in cMYC and Immunoglobulin heavy-chain gene (IGH) with detailed characterization of its variant rearrangement. Short-term follow-up post R-CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone) therapy seemed to be favorable. Accumulation of many more literature studies on such cases with their therapeutic implications would lead to the categorization of these cases as a separate subclass in large B-cell lymphomas followed by molecular targeted therapy.

Dorsal approach in transfer of the distal spinal accessory nerve into the suprascapular nerve: histomorphometric analysis and clinical results in 14 cases of upper brachial plexus injuries.

PURPOSE: The spinal accessory nerve (SAN) is conventionally transferred to the suprascapular nerve (SSN) through an incision in the supraclavicular region (the anterior approach) to improve shoulder function in brachial plexus injuries. This approach carries a risk of partial denervation of upper trapezius muscle. Here we describe how dorsal nerve transfer through an incision placed directly over the scapular spine preserves the proximal branches to the upper trapezius muscle and allows nerve transfer close to target muscles. METHODS: We report our experience with the dorsal approach in 14 cases managed between February 2007 and January 2008. Results were compared with 21 control cases treated by the anterior approach. In addition, we submitted proximal cut ends of the SAN in 10 cases from the experimental group for histomorphometry. RESULTS: A total of 11 patients had C5 and C6 injuries, whereas 3 had associated C7 injuries. The denervation period ranged between 3 and 10 months. In all cases, the distal SAN could be transferred to the SSN without a graft. Histomorphometry revealed an average of 1,671 myelinated axons. Shoulder abduction and external rotation were restored in 13 and 9 cases, respectively, compared with 16 and 12, respectively, in the control group. Electromyography revealed the first sign of reinnervation of infraspinatus muscle at 23 ± 4 weeks, compared with 30 ± 4 weeks in the control group. Initial evidence of shoulder abduction appeared earlier in the study population (28 ± 4 vs 34 ± 4 weeks). Shoulder abduction and external rotation in the study group ranged between 70° and 170° and 30° and 80°, compared with 65° and 160° and 22° and 55° in the control group. Using the Medical Research Council (MRC) grading system, at 6 months postreconstruction, 13 patients had M4 power in the trapezius muscle, whereas 1 had M3, compared with 5 in the control group who displayed grade 3 weakness. CONCLUSIONS: A dorsal approach for transfer of the distal SAN into the SSN is an alternative and effective technique in restoring shoulder function in upper brachial plexus injuries. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.

Fascicular selection for nerve transfers: the role of the nerve stimulator when restoring elbow flexion in brachial plexus injuries.

PURPOSE: Restoration of elbow flexion is an important goal in brachial plexus injuries. Double nerve transfers using fascicles from ulnar and median nerves have consistently produced good results without causing functional compromise to the donor nerve. According to conventional practice, these double nerve transfers are dependent on the careful isolation of ulnar and median nerve fascicles, which are responsible for wrist flexion, using a handheld nerve stimulator. Here we suggest that fascicular selection by nerve stimulation might not be a necessity when executing double nerve transfers for restoration of elbow flexion in brachial plexus injuries. METHODS: This is a retrospective case control study in 26 patients with C5, C6 brachial plexus injuries that were managed with double nerve transfers between March 2005 and January 2008. Our technique consisted of transferring 2 fascicles, one each from the ulnar and the median nerve, directly onto the biceps and brachialis motor branches. Contrary to the standard practice, the ulnar or median nerve fascicles were selected without using a handheld nerve stimulator. Results were compared to 21 cases (control group) in which a nerve stimulator was used for fascicular selection. The denervation period ranged from 3 to 9 months. RESULTS: Twenty-four patients of the study group experienced full restoration of elbow flexion, and 2 had an antigravity flexion of 120° and 110°. The EMG revealed the first sign of reinnervation of biceps and brachialis muscle at 9 ± 2 weeks and 11 ± 2 weeks, as compared to 9 ± 2 weeks and 12 ± 4 weeks in the control group. After surgery, the appearance of initial evidence of elbow flexion, the range and mean of elbow flexion strength, and the difference between preoperative and postoperative grip and pinch strengths were comparable in both groups. At 24 to 28 months follow-up, 19 patients of the study group had M4 power and 7 had M3, compared to 18 and 3 cases, respectively, in the control group. The P values for Medical Research Council grade, strength of elbow flexion, and range of elbow flexion between the 2 groups did not reveal any significant statistical difference. CONCLUSIONS: Double nerve transfer is a reliable technique for restoring elbow flexion in brachial plexus injuries. There is no advantage of using a nerve stimulator in selecting fascicles before performing the nerve transfer.

Histopathological Evaluation of Inferior Alveolar Neurovascular Bundle in Cases of Trigeminal Neuralgia.

BACKGROUND: Trigeminal neuralgia is a painful disease that has been afflicting mankind since time immemorial. The etiology and pathophysiology have been widely studied but poorly understood. There are well-documented researches analyzing ultrastructural changes in trigeminal root specimens obtained following microvascular decompression surgery. However, there are no studies evaluating microscopic changes following peripheral neurectomy. PURPOSE: The present study examined microscopic changes in inferior alveolar neurovascular bundle in trigeminal neuralgia patients of mandibular division with no underlying cause. MATERIALS AND METHODS: The biopsy specimens were obtained from peripheral neurectomy of 11 trigeminal neuralgia patients' refractory to anti-neuralgic medications. The autopsy specimens from 10 cadavers were used as control. The specimens were subjected to histopathological examination by hematoxylin and eosin, Masson trichrome and Luxol fast blue stains. RESULTS: All biopsy specimens reported luminal occlusion of small vessels, medial degeneration and intense mononuclear inflammatory infiltrate. Focal myelin digestion chambers were observed in large and small axons. No pathological alterations of either blood vessel or nerve fibers were reported in autopsy specimens. CONCLUSION: The demyelination of inferior alveolar nerve due to pathologic vascular changes in peripheral vasculature may have a role in initiation and precipitation of trigeminal neuralgia, and hence, peripheral neurectomy has a significant role in alleviating pain.

Indian Academy of Cytologists Guidelines for Collection, Preparation, Interpretation, and Reporting of Serous Effusion Fluid Samples.

Cytological examination plays an important role in the initial work-up of the serous cavity effusion fluids to find out the possible etiology as benign or malignant. Among malignant effusions, cytology is helpful in determining the exact type, site, and stage of the tumor. However, for reporting effusion cytology specimens, there is no consistent and reproducible reporting system. AIMS: The aim of these guidelines is to provide a standardized format for effusion cytopathology right from sample receipt to its ultimate report sign-out for implementation in all cytopathology laboratories. The Indian Academy of Cytologists in consultation with experts across the country has prepared guidelines pertaining to collection, preparation, and diagnostic categories of effusion specimens to reduce reporting variability. The guidelines are made keeping in mind the different areas of practices in India, especially low- and medium-resource settings. The guidelines are broadly divided into essential, optimal, and optional categories for best usage and appropriate allocation of the precious specimens. In referral centers or well-established setups, essential ancillary techniques can be done for accurate and final diagnosis. By adhering to and implementing these uniform guidelines, it is hoped that clinical patient care and management in India will improve and be of uniformly good quality by enabling and facilitating good laboratory practices.

Indian Academy of Cytologists National Guidelines for Cytopathology Laboratories for Handling Suspected and Positive COVID-19 (SARS-CoV-2) Patient Samples.

COVID-19, caused by the SARS-CoV-2 virus, has been declared a pandemic by the World Health Organization. This scenario has impacted the way we practice cytopathology. Cytology laboratories receive fresh and potentially infectious biological samples including those from the respiratory tract, from COVID-19 positive or suspected patients. Hence, the Indian Academy of Cytologists thought it necessary and fit to bring forth appropriate guidelines starting from transportation, receipt, processing, and reporting of samples in the COVID-19 era. The guidelines are prepared with the aim of safeguarding and protecting the health care personnel including laboratory staff, trainees and cytopathologists by minimizing exposure to COVID-19 so that they remain safe, in order to able to provide a continuous service. We hope that these national guidelines will be implemented across all cytopathology laboratories effectively.

Performance of A Convolutional Neural Network in Screening Liquid Based Cervical Cytology Smears.

CONTEXT: Cervical cancer is the second most common cancer in women. The liquid based cervical cytology (LBCC) is a useful tool of choice for screening cervical cancer. AIMS: To train a convolutional neural network (CNN) to identify abnormal foci from LBCC smears. SETTINGS AND DESIGN: We have chosen retrospective study design from archived smears of patients undergoing screening from cervical cancer by LBCC smears. MATERIALS AND METHODS: 2816 images, each of 256 × 256 pixels, were prepared from microphotographs of these LBCC smears, which included 816 "abnormal" foci (low grade or high grade squamous intraepithelial lesion) and 2000 'normal' foci (benign epithelial cells and reactive changes). The images were split into three sets, Training, Testing, and Evaluation. A convolutional neural network (CNN) was developed with the python programming language. The CNN was trained with the Training dataset; performance was assayed concurrently with the Testing dataset. Two CNN models were developed, after 20 and 10 epochs of training, respectively. The models were then run on the Evaluation dataset. STATISTICAL ANALYSIS USED: A contingency table was prepared from the original image labels and the labels predicted by the CNN. RESULTS: Combined assessment of both models yielded a sensitivity of 95.63% in detecting abnormal foci, with 79.85% specificity. The negative predictive value was high (99.19%), suggesting potential utility in screening. False positives due to overlapping cells, neutrophils, and debris was the principal difficulty met during evaluation. CONCLUSIONS: The CNN shows promise as a screening tool; however, for its use in confirmatory diagnosis, further training with a more diverse dataset will be required.

Pilot Study of an Open-source Image Analysis Software for Automated Screening of Conventional Cervical Smears.

INTRODUCTION: The Pap stained cervical smear is a screening tool for cervical cancer. Commercial systems are used for automated screening of liquid based cervical smears. However, there is no image analysis software used for conventional cervical smears. The aim of this study was to develop and test the diagnostic accuracy of a software for analysis of conventional smears. MATERIALS AND METHODS: The software was developed using Python programming language and open source libraries. It was standardized with images from Bethesda Interobserver Reproducibility Project. One hundred and thirty images from smears which were reported Negative for Intraepithelial Lesion or Malignancy (NILM), and 45 images where some abnormality has been reported, were collected from the archives of the hospital. The software was then tested on the images. RESULTS: The software was able to segregate images based on overall nuclear: cytoplasmic ratio, coefficient of variation (CV) in nuclear size, nuclear membrane irregularity, and clustering. 68.88% of abnormal images were flagged by the software, as well as 19.23% of NILM images. The major difficulties faced were segmentation of overlapping cell clusters and separation of neutrophils. CONCLUSION: The software shows potential as a screening tool for conventional cervical smears; however, further refinement in technique is required.

Clear cell sarcoma arising from paraspinal ligament of thoracic spine: Report of an unusual case.

Clear cell sarcoma (CCS) is an unusual but aggressive soft-tissue tumor with an incidence of <1% of all soft-tissue sarcomas. It was previously termed "malignant melanoma of soft parts" due to its resemblance clinically and morphologically. Normally CCS is seen in patients aged 20-40 years. A rare case of CCS of paraspinal ligament in a 5-year-old boy is being reported. Histopathology and immunohistochemistry markers confirmed the diagnosis. The present case is unique since the entity itself is rare and also due to its occurrence in a child.

A study of BRAF mutation in colorectal carcinoma in Indian population.

CONTEXT: BRAF mutation has been extensively studied and associated with various tumors. Targeted therapeutic intervention against BRAF mutation is established modality against many such tumors. Various studies have estimated that the prevalence of BRAF mutation in colorectal carcinoma (CRC) is 5%-25%. Considering epidemiology differences from Western population and paucity of studies on BRAF mutation in CRC in Asian patients, the present study was done to study the BRAF mutation in CRC in Indian population. AIMS: The aim is to study the distribution of BRAF mutation and its correlation with the American Joint Committee on Cancer (AJCC) stage, grade, and other clinicopathological parameters in CRC. SETTINGS AND DESIGN: This was a cross-sectional study. SUBJECTS AND METHODS: Immunohistochemistry study was done using BRAFV600E monoclonal antibody (Clone VE1) for 65 consecutive cases of CRC in a tertiary care center. The results were statistically analyzed using SPSS version 2.0. RESULTS: This study found that BRAF mutation is not significantly present in CRC as only 4.6% of cases were positive for BRAFV600E mutation. However, there was statistically significant relation between increasing AJCC stage and BRAF mutation. CONCLUSIONS: This study concluded that BRAF mutation is not prevalent in Indian population with CRC. However, it is significantly related with advanced AJCC stages.

Cerebral blastomycosis: a case report.

Blastomycosis is a chronic systemic fungal infection characteristically affecting the skin and lungs. Involvement of the central nervous system (CNS) is unusual, with cases generally presenting with meningitis, and rarely as intracranial mass lesion and solitary or multiple abscesses. Only two cases of intracranial extra-axial blastomycosis have been reported from India, and we report the third case, which presented as meningioma in a 23-year old female.

Correlation of diagnostic yield of stereotactic brain biopsy with number of biopsy bits and site of the lesion.

Our objective was to examine the reliability of histological diagnosis achieved vis a vis the number of biopsy bits obtained along a single trajectory of the stereotactic needle. A retrospective analysis of stereotactic biopsies performed in a single tertiary care neurosciences center, during a period of 11 years, between 1995 to 2005 was done. The overall diagnostic accuracy achieved on histopathology was correlated with the number of bits obtained by stereotactic biopsy. A total of 86 cases were analyzed, which consisted of 58 males and 28 females. Age ranged from 6 to 75 years, with a mean age of 36.1 years. Twenty percent of the patients were in the pediatric age group and 15% were > or =60 years of age. Most common sites biopsied were thalamus/basal ganglia (55.8%), followed by eloquent areas and other sites. A definitive histological diagnosis was established in 70 cases (diagnostic yield, 81.3%), which encompassed 65 neoplastic and 5 nonneoplastic lesions. Astrocytic lesions, the most common, include 10 pilocytic astrocytomas (PA), 29 diffuse astrocytomas (DA), 11 anaplastic astrocytomas (AA), and 7 glioblastoma multiforme (GBM). In 16 cases no definite histological diagnosis could be offered. The number of biopsies ranged between 1 and 6 bits (mean, 2; median, 1). The majority (68.7%) of the biopsies were 1 or 2-bits. The diagnostic accuracy increased from 76.5% for single biopsies to 84% and 88.2% for 2 and 3 bits, respectively, and 100% for biopsies with 5 to 6 bits. Overall, a trend of higher diagnostic yield was seen in cases with more biopsies when compared with single bit biopsies. Thus, this small series confirms that stereotactic procedures involving multiple bits are associated with a high diagnostic yield.

Neuropathological spectrum of pilocytic astrocytoma: an Indian series of 120 cases.

Pilocytic astrocytomas (PAs) are generally well circumscribed, slowly growing, cystic tumors, occurring in the pediatric age group. Our aims were to retrospectively analyze the neuropathological spectrum of PA, and correlate it with various clinicopathological features. A total of 120 PAs, diagnosed and managed at this center during a 5-year period, were included. The study population had a mean age of 18.9 years, with male predominance (68.3%), and demonstrated predilection for posterior fossa (61.7%). On histopathology, biphasic pattern (89.2%) along with Rosenthal fibers (66.7%) and eosinophilic granular bodies (60%) were present in the majority of cases. Vascular features were characterized by perivascular hyalinization (51.7%), angiomatous proliferation (21.7%) and glomeruloid changes (21.7%). Hemosiderin-laden macrophages were noted in 37.1% of cases. Further, 60.8% showed lymphoplasmacytic infiltration, while atypia and necrosis were present in 25.8% and 1.7% of cases, respectively. Statistical evaluation revealed significant correlation of angiomatous proliferation with age (< or =12 and >12-year age groups) (p=0.011); and of hemosiderin deposition with angiomatous proliferation (p=0.006), perivascular hyalinization (p=0.035), and age (< or =12 and >12-year age groups) (p=0.028). This study emphasizes that though PAs generally display classical histomorphology, diagnosis may be challenging in patients with unusual clinicopathological features, e.g. in older patients, uncommon location, absence of biphasic pattern, or presence of nuclear atypia, mitotic figures and necrosis, and also in cases of small biopsies. In the absence of diagnostic histology enumerated above, vascular features like angiomatous proliferation, glomeruloid changes and perivascular hyalinization, along with hemosiderinladen macrophages and perivascular lymphocytic infiltration should be considered as surrogate histological markers of PA.