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Biomedical subjects

R K Vasishta

Publications and source records attributed to R K Vasishta.

At least 19 recordsLinked to original sources
PubMed2006

Demyelinating disease simulating brain tumours: a histopathologic assessment of seven cases.

BACKGROUND: Demyelinating diseases can present as space occupying lesions with in the brain. It is clinically and radiologically difficult to differentiate them from primary neoplasms. Histopathologically they mimic astrocytic neoplasms closely and identifying these lesions correctly has a profound impact in treatment and prognosis of these patients. AIMS AND OBJECTIVES: The objective was to determine the histopathologic features of such acute focal demyelinating disease that clinically presented as brain tumors. MATERIAL AND METHODS: Seven cases were included for the study. Detailed histopathological examination including stains for myelin and axon were performed. The histopathological keys in arriving at the right diagnoses included a well demarcated lesion that contains uniform distribution of foamy macrophages in the absence of any associated coagulative necrosis, sheets of gemistocytic astrocytes in the white matter that show well-formed processes, perivascular chronic inflammatory cell infiltration and total absence of myelin with relative preservation of axons within these areas. CONCLUSION: The degree of suspicion (clinical, radiological and histopathological) should be high to diagnose these group of lesions. The above-mentioned diagnostic keys should help in arriving at the correct histopathological diagnoses of such cases.

Adult↗
PubMed2006

Central neurocytoma: a clinico-pathological study of eight cases.

Central neurocytomas are benign neuronal tumours generally found in the lateral or third ventricles. They are rare, comprising < 1% of all brain tumours. It is frequently confused with other tumours of the central nervous system particularly oligodendroglioma. The present study was done to analyse the histopathological features including immunohistochemical profile of these rare tumours. Eight cases were taken up for the study. Seven of the cases had an intraventricular location and one was located outside the ventricles. Increased intracranial pressure was the most common presenting symptom. Microscopically all tumours were composed of small uniform cells with perinuclear halos and regular round nuclei. The tumour in extraventricular location showed atypical features. Immunohistochemistry showed positivity for neuronal markers. The present series highlights the characteristic clinical and pathological findings of this rare brain tumour. Immunostaining for neuronal markers are essential for distinguishing them from other small round cell tumours of the brain.

Adolescent↗
PubMed2005

Fatal acute disseminated encephalomyelitis following treated snake bite in India.

Snake bite is an important cause of mortality and morbidity in India, with an estimated 35,000 to 50,000 fatal bites occurring annually. The neurological consequences of snake bite are predominantly the result of inhibition of neuromuscular transmission. We describe the first documented case of autopsy proven acute disseminated encephalomyelitis following treated snake bite in a young female.

Adult↗
PubMed2004

Comparison of cytologic features of giant-cell tumor and giant-cell tumor of tendon sheath.

The cytologic features in twelve cases of giant-cell tumor (GCT) and five cases of giant-cell tumor of tendon sheath (GCTTS) diagnosed by fine-needle aspiration cytology (FNAC) are described. All of these cases were histopathologically confirmed. The aspirates of GCT are composed of a dual population of mononucleated spindle cell and multinucleated giant cells. The peripheral adherence of giant cells to the spindle cell is the feature of diagnostic significance in GCT. In GCTTS, the aspirate consists of a polymorphic population composed of mononuclear histiocyte-like cells, hemosiderin laden macrophages, foamy macrophages, and a few multinucleated giant cells. FNAC can be used as a diagnostic tool for an early and accurate detection of these two giant cell-rich lesions, since the cytologic features when evaluated in conjunction with the clinical and radiologic features are sufficiently diagnostic.

Adult↗
PubMed2004

Cytologic features of central giant-cell granuloma of the jaw.

In this present series, we studied in detail the cytologic features of five histopathologically verified cases of central giant-cell granuloma (CGCG). All the patients in this series were female, with an age range of 11-60 years. There were three cases with involvement of the lower jaw and two cases had upper jaw involvement. Cytology smears showed dispersed single cells in the background. Nuclei of the individual cells were round to ovoid with fine chromatin and inconspicuous nucleoli. The cytoplasm of these cells was moderate in amount with indistinct cell borders. Many randomly scattered multinucleated giant cells with 10-20 nuclei were present in the background. Combination of clinical features, radiologic pictures, and cytologic features may be helpful for diagnosis of CGCG on fine-needle aspiration cytology.

Adolescent↗
PubMed2004

Chondrosarcoma of calcanaeum in a 12-year-old male patient: a case report.

Chondrosarcoma is distinctly uncommon and tends to be located often in the extremities in young patients more than in its adult counterpart. Cartilaginous tumors involving the small bones of the hands and feet are benign tumors such as enchondromas, chondromyxoid fibroma (CMF), and chondroblastoma. Chondrosarcomas involving calcanaeum in young adults are largely covered in the literature as single case reports. A young 12-yr-male patient presented with complaints of pain and mild swelling in the ankle. Radiological examination revealed a dense irregular lesion in the calcanaeum. Fine-needle aspiration was performed and a possibility of chondrosarcoma was suspected, which later was confirmed on histopathological examination. The cytopathologist should be aware of the occurrence of malignant chondroid tumors in the younger age group at this rare site. Correlation to radiological findings is essential in these cases.

Biopsy, Fine-Needle↗
PubMed2004

Role of fine needle aspiration cytology in the diagnosis of soft tissue tumours and tumour-like lesions.

In this study, we evaluated the usefulness of fine needle aspiration cytology (FNAC) in the diagnosis of soft tissue tumours. We have also assessed the various pitfalls of FNAC of soft tissue tumours. This was a retrospective study and here we analysed only 82 histopathology proven cases of FNAC of soft tissue tumours diagnosed in a five and half year period. On histopathological examination, 55 of these cases were malignant and 27 were benign. There was a total of 15 recurrences and histopathology was available prior to FNAC in only eight of these cases. Therefore, excluding these eight cases, malignant tumours were primarily diagnosed by FNAC in 47 cases. The sensitivity, specificity and positive predictive value of FNAC in diagnosis of soft tissue tumours were 91.5%, 92.5% and 95.5%, respectively. Only 22 of 47 cases (46.8%) were correctly categorized. There were two false-positive and four false-negative cases. One case each of fibromatosis and schwannoma were reported as sarcoma. False-negative cases were fibrosarcoma (1), malignant nerve sheath tumour (2) and haemangiopericytoma (1). FNAC was very useful in distinguishing benign from malignant soft tissue tumours. However, it was not so effective in exact categorization of tumours.

Biopsy, Fine-Needle↗
PubMed2004

Botryomycosis--a series of six integumentary or visceral cases from India.

Botryomycosis is characterized by a chronic suppurative lesion with distinctive fungus-like grains that resemble the sulphur granules of actinomycosis. Both integumentary and visceral forms of the disease are recognized. The visceral involvement occurs predominantly in the lungs. Botryomycosis may develop in apparently healthy individuals as well as the immunologically compromised. Six cases of botryomycosis, affecting various sites in the bodies of immunocompetent individuals, are described. In each of the six cases, the initial clinical diagnosis was of an abscess or malignancy.

Abscess↗
PubMed2004

Calvarial malignant fibrous histiocytoma.

Primary malignant fibrous histiocytoma (MFH) of the central nervous system (CNS) is uncommon. We report cases of two young patients of MFH arising from the cranial meninges and involving the adjacent skull and scalp. There was infiltration of the brain in one case. Both the lesions were excised and primary scalp repair was performed.

Adult↗
PubMed2003

Subependymomas in children: a report of five cases including two with osseous metaplasia.

Subependymomas are highly differentiated slow growing gliomas. They are one of the few gliomas which are biologically benign. They are extremely rare in children. However, after going through the histopathology records of our department of fourteen years (1983-1997) we found that five (20%) cases of subependymomas have been diagnosed in children out of a total of twenty-six subependymomas. Two of our cases showed the presence of osseous metaplasia, a hitherto undescribed finding.

Brain Neoplasms↗
PubMed2002

Expression of Bcl2 proto-oncogene in primary tumors of the central nervous system.

The present study was addressed to find out the expression of Bcl2 proto-oncogene in tumor tissues derived from 25 patients with primary central nervous system tumors. Brain parenchyma in 8 cases, with deeply located tumor, was also examined for Bcl2 expression which served as control. Both benign and malignant tumors (confirmed by histopathological examination) expressed Bcl2 gene product. Tumors exhibited 2-6 fold increase in Bcl2 expression as compared to the normal parenchyma adjacent to some of these tumors studied. However, no correlation was found between the histopathological types of tumor, glial fibrillary acidic protein positivity and degree of Bcl2 expression. Based on this study, we propose that the overexpression of Bcl2 gene product found in primary CNS tumors may be an important molecular event which is known to make the various types of tumor resistant to chemotherapy or radiotherapy.

Adenoma↗
PubMed2001

Central nervous system complications in renal transplant recipients in a tropical environment.

Renal transplant recipients are at risk of developing various infectious and non-infectious complications affecting the central nervous system (CNS). There is paucity of data regarding the spectrum of CNS complications and the epidemiology of infective agents varies according to geographical location. We retrospectively studied the spectrum of CNS complications seen in 792 renal allograft recipients followed up at this tertiary care centre in north India over a 19-year period. Autopsy findings of 78 allograft recipients who died in the hospital were also reviewed and included. The brain was examined in 22 of these patients. Overall, 79 (10%) patients developed some form of CNS dysfunction with a mortality rate of 60.8%. CNS infections occurred in 31 renal allograft recipients (3.9% of total) and accounted for the largest group (39.2%). Fungi were the commonest etiological agents (21 patients) and were associated with a 70% mortality, with cryptococcal meningitis occurring in 12, mucormycosis in six, aspergillosis in one, and other unusual fungal infections in the remaining two patients. All patients with mucormycosis had a fatal outcome. The second largest group comprised of patients with non-uremic encephalopathies (23 patients, 29.1%) with metabolic encephalopathy occurring in 13, toxic encephalopathy in nine and hypertensive encephalopathy in one patient) and was associated with an overall mortality rate of 60.9%. Cerebrovascular accidents occurred in 12 patients (15.2%) and were associated with a mortality of 91.7%. Other CNS complications included treatment related complications in four (5.1%), primary CNS lymphomas in three (3.8%), and miscellaneous complications in six patients (7.6%). Patients with non-cryptococcal fungal infections of the CNS, hepatic and toxic encephalopathy and those with cerebrovascular accidents had the worst outcome. There was no relationship between the development of infection or stroke and the type of maintenance immunosuppression used. We conclude that complications involving the CNS occur in 10% of all renal transplant recipients and are associated a with high mortality, warranting early diagnosis and aggressive treatment.

Adolescent↗