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Biomedical subjects

C Sarkar

Publications and source records attributed to C Sarkar.

At least 127 records · Page 7Linked to original sources
PubMed1990

A clinico-pathologic study of pituitary adenomas.

One hundred patients of pituitary adenoma were studied using light microscopy, electron microscopy, immunohistochemistry and serum hormone estimation. Depending on the absence or presence of clinical endocrine manifestation they were divided into 2 groups 'non-functioning' (group I -48 patients) and 'hyper-functioning' (group II- 52 patients). Tumours in group I were chromophobes, some of which (group IA) had no hormone increase in serum nor detection in tissues and ultrastructurally they consisted of secretorily inactive cells (null cell adenomas) while others (group IB) were composed of secretorily active cells with prolactin consistently increased in serum and localized in tissue (lactotroph adenomas). Tumours in group II were chromophobe, acidophil, basophil or mixed adenomas with varying number of secretorily active cells in all. The hormone responsible for the hyperfunction was always raised in serum and localized in tissue. Thus growth hormone was demonstrated in all tumours from patients with acromegaly (somatotroph adenomas), prolactin in all tumours from patients with galactorrhea (lactotroph adenomas) and ACTH in all tumours from patients with Cushing's syndrome (corticotroph adenomas). It was observed, however, that 40 per cent of tumours were pleurihormonal, growth hormone and prolactin being the commonest combination. Interestingly, not all the hormones localized by immunohistochemistry in pleurihormonal adenomas were detected in serum and/or reflected in the clinical picture.

Adenoma↗
PubMed1989

Ultrastructural study of micro-blood vessels in human brain tumors and peritumoral tissue.

Ultrastructural and tracer studies have demonstrated that vasogenic edema, a serious complication of brain tumor is the result of increased permeability of tumor vessels. However, not much information is available on the alterations in the vessels in the peritumoral areas. Therefore, we studied the ultrastructural changes in the tumor micro-blood vessels (MBVs) in 20 cases of glioma and compared these with the changes in the peritumoral MBVs in 10 of these cases. The tumor MBVs showed remarkable structural changes, viz, increase in pinocytotic vesicles, large vacuoles and microvilli in the endothelial cells, varying degrees of endothelial attenuation and fenestration, an occasional partially or completely opened-up junction and some pale and edematous endothelial cells, which can adequately explain their increased permeability. The peritumoral MBVs also showed evidence of increased permeability in the form of increased pinocytotic vesicles, large vacuoles and microvilli associated with pale and edematous cytoplasm of some endothelial cells. Thickened multilayered basement membrane, absence of ensheathment of capillary basement membrane by astrocytic cell processes and widened perivascular space were observed in both tumoral and peritumoral MBVs. An interesting observation was that in the peritumoral MBVs, the pinocytotic vesicles were most conspicuously seen on the abluminal side of the endothelial cells often fused with the abluminal plasma membrane. Although a static study like this cannot indicate any definite direction of movement of fluid, we feel that the occurrence of reverse pinocytosis is a distinct possibility in the peritumoral MBVs and that it may be an important means of resorption of edema fluid.

Basement Membrane↗
PubMed1989

Cystic medulloblastoma.

In children medulloblastoma is a commonly encountered posterior fossa midline tumour in which cystic degeneration is not uncommon. A cystic medulloblastoma without solid component has, however, not been described. We report a 12-year-old boy with a posterior fossa midline cystic lesion on CT with surgical and histological confirmation of the diagnosis.

Cerebellar Neoplasms↗
PubMed1989

Cladosporiosis (cerebral phaeohyphomycosis) of brain--a case report.

A case of cerebral cladosporiosis caused by Cladosporium trichoides (bantianum) now known as Xylohypha bantiana is described and illustrated. Predisposing debilitating diseases were not detectable. The Cladosporiosis diagnosis was based on visualisation of hyphal element in direct Gram's stain, direct KOH preparate of pus from brain abscess and on repeated successful cultivation of Cladosporium trichoides from specimen and by histopathology. Following surgery and anti-fungal chemotherapy the patient was cured.

Adult↗
PubMed1989

Primitive neuroectodermal tumours of the central nervous system--an electron microscopic & immunohistochemical study.

A series of 75 poorly differentiated neoplasms of the central nervous system viz., medullo-blastoma, cerebral neuroblastoma, pineoblastoma and ependymoblastoma were studied by light microscopy (LM), electron microscopy (EM) and immunohistochemistry (IH). Although the predominant cells constituting these tumours appeared to be undifferentiated cells by LM and EM, many others showed evidence of differentiation into glial, neuronal or ependymal cell lines by EM and IH. It is therefore, concluded that all these neoplasms are best considered as primitive neuroectodermal tumours and these may be classified as such in neuro-oncology. They may be subclassified further on the basis of differentiation into one or more cell lines.

Brain Neoplasms↗
PubMed1989

Medullomyoblastoma. A case report.

A case of medullomyoblastoma was studied by light and electron microscopy and by immunohistochemistry. It showed glial and neuronal differentiation in the medulloblastoma areas and rhabdomyoblastic differentiation in the intervening areas.

Cerebellar Neoplasms↗
PubMed1989

Contralateral hemiplegia in herpes zoster ophthalmicus. Role of temporal artery biopsy.

We describe clinical, radiological and pathological findings in a case of herpes zoster ophthalmicus who developed contralateral hemiplegia. The CT scan showed discrete infarction of the right internal capsule and the right carotid angiogram showed concentric narrowing of the supraclinoid portion of right internal carotid artery. Superficial temporal artery biopsy showed infiltration by lymphocytes and plasma cells without any granuloma formation or giant cells. The importance of trigemino-vascular connections in the pathogenesis of this complication of herpes zoster ophthalmicus and the role of temporal artery biopsy in the diagnosis of arteritis following herpes zoster are discussed.

Biopsy↗
PubMed1988

Oligodendroglial tumors. An immunohistochemical and electron microscopic study.

Fifty-five cases of oligodendrogliomas and mixed oligoastrocytomas were evaluated using immunohistochemical (IH) study for glial fibrillary acidic protein (GFAP) and electron microscopic (EM) study. Most of the tumors in both of these groups showed many neoplastic oligodendroglial cells with GFAP-positive staining in their cytoplasm by IH study. By EM study too, many tumor cells showing features of oligodendroglial cells contained intermediate filaments. Our observations suggested the presence of a transitional form of cells in these tumors. The current study supports the contention that both oligodendrogliomas and oligoastrocytomas arise from a common progenitor cell capable of differentiation into both oligodendrocyte and astrocyte. The nature and degree of differentiation depends probably on gene expression and/or some microenvironmental factors.

Brain Neoplasms↗
PubMed1988

Fine-needle aspiration cytology of meningiomas with unusual presentations.

Meningiomas are not often aspirated unless they erode the skull, occur intraorbitally, or present as swelling in the head and neck region. We describe the cytologic findings of fine-needle aspiration cytology (FNAC) in four cases of meningioma that presented with swellings in the head and neck region. The patients underwent surgery, and the diagnosis of meningioma was confirmed. Three of the four cases were reported as aggressive meningiomas on histopathology.

Adult↗
PubMed1987

Cranio-cerebral erosion (growing fracture of the skull in children). Part I. Pathology.

Seventeen cases of cranio-cerebral erosion were subjected to detailed histopathological study in order to get a better insight into the pathogenesis of this lesion. It was found that the bone and brain at the site and edge of the defect show not only evidence of damage at the time of initial injury, but also of "active" progressive damage months and years later. The possible causes for continuing damage to the brain and bone are discussed.

Brain↗
PubMed1987

Intracerebellar schwannoma. Case report.

A rare case of a solitary schwannoma arising within the cerebellum is reported. The diagnosis was confirmed by electron microscopy and immunohistochemical staining.

Adult↗
PubMedDate not supplied

Primary cerebral rhabdomyosarcoma.

Primary intracranial rhabdomyosarcomas are extremely rare tumors; those in the supratentorial location are commoner in adults. A 10 year old girl with primary cerebral rhabdomyosarcoma is presented.

Brain Neoplasms↗
PubMedDate not supplied

Pigmented medulloepithelioma: report of a case and review of the literature.

A 9-year-old male child had a IV ventricular medulloepithelioma of classical histology, showing tubulopapillary and undifferentiated areas. The unusual feature, however, was the presence of melanin pigmentation in the cells, which was further confirmed by electron microscopy. So far 28 cases of medulloepithelioma have been reported in the English literature. However, none of them showed melanin pigmentation. To the best of our knowledge this is the first case of pigmented medulloepithelioma in the English literature.

Biomarkers, Tumor↗