Subimal Roy

Medullomyoblastoma : a teratoma

Three cases of medullomyoblastoma in children are reported. The second case is unique in that in addition to areas of medulloblastoma and rhabdomyosarcoma, there were areas of well‐differentiated teratoma containing all mature elements. This observation lends support to the teratomatous nature of medullomyoblastoma.

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

SummaryUltrastructural 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.

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.

Rosenthal fibres: an immunohistochemical, ultrastructural and immunoelectron microscopic study.

SummaryThe nature of Rosenthal fibres (RF) was investigated in eight cases each of low-grade astrocytoma and reactive gliosis using immunohistochemical (IH) staining for glial fibrillary acidic protein (GFAP), electron microscopy (EM) and immunoelectron microscopy (IEM) by immunogold labelling technique. By IH under light microscopy (LM), three types of RF were seen, uniformly positive (type I), rim positive (type II) and completely negative (type III). EM showed variation in structural pattern of RF. Some RF contained large amount of glial filaments (GF) intermingled with RF while others with a large amount of electron dense material and less GF. Thus, the presence and amount of GF in RF appear to be responsible for the different types of IH staining under LM. IEM showed that all RF including the ones consisting of entirelh amorphous material possess immunoreactivity for GFAP.It is suggested that RF formation is a two-stage process, staring with excessive accumulation of GF within astrocytic processes followed by their gradual alteration into electron-dense amorphous material under the influence of some unknown metablic or other factors. The quantitative analysis of different types of RF suggests a difference in the rate of formation of RF in neoplastic and reactive conditions.

A transmission and scanning electron microscopic study of tumoral and peritumoral microblood vessels in human gliomas.

SummaryThe tumor microblood vessels (MBVs) of 25 cases of gliomas of varying grades were studied and compared with those in peritumoral region using both transmission and scanning electron microscopy (TEM and SEM). The TEM study revealed numerous villous projections with pinocytotic vesicles (PCVs) and large vacuoles (LVs) concentrated mainly at the luminal aspect in tumor MBVs which increased with increasing severity of edema. The peritumoral MBVs, in addition to showing some increase in villous projections on the luminal surface, also showed increased number of PCVs and LVs concentrated at the abluminal aspect with some of them even communicating with the extravascular space. The SEM study largely corroborated the TEM findings. The sites of formation of PCVs and LVs appeared as small pits or large craters on the luminal surface of the endothelial cells of tumor MBVs. We feel that the morphological evidence of increased permeability in tumor MBVs represents their role in the development of edema and that the occurrence of reverse pinocytosis in peritumoral MBVs is a distinct possibility which may be associated with resorption of edema fluid.

Benign nerve sheath tumors: A light microscopic, electron microscopic and immunohistochemical study of 102 cases

&NA; One hundred and two cases of benign nerve sheath tumors (NSTs) were studied with a combined approach using routine light microscopy (LM), immunohistochemistry (IH) for myelin basic protein (MBP) and S‐100 protein as well as transmission electron microscopy (TEM) with the aim of obtaining greater insight into the true nature of these neoplasms, and also to establish the importance of IH and TEM in their diagnosis. Myelin basic protein was not identified in any of these tumors, whereas S‐100 protein was positive to a variable degree in both schwannomas and neurofibromas. TEM revealed that Schwann cells predominated in tumors which were strongly positive for S‐100 protein and appeared as schwannomas by LM. However, neurofibromas showing a variable patchy positivity for S‐100 were composed of an admixture of Schwann cells, fibroblast‐like cells and intermediate cells considered to be modified Schwann cells. Perineurial cells in typical form were not seen. It is concluded that all NSTs are basically of Schwann cell origin and that the intermediate cells and fibroblast‐like cells are variants of Schwann cells. The different morphological appearances and biological behaviour of schwannomas and neurofibromas may be related to some other factors like micro‐environment or genetic predisposition. Further, both IH, especially for S‐100 protein, and TEM play an important role in establishing their diagnosis.

Multiple primary tumors of the brain including a medulloblastoma in the cerebellum.

A case of multiple primary tumors in a 12‐year‐old girl is described. The tumors included a right optic nerve glioma, a pilocytic astrocytoma in the right globus pallidus, a ganglioglioma in the left globus pallidus and a medulloblastoma in the cerebellum. To our knowledge no such case has been reported so far in literature.

IN-VIVO PROLIFERATIVE POTENTIAL OF PRIMARY HUMAN BRAIN TUMORS; ITS CORRELATION WITH HISTOLOGICAL CLASSIFICATION AND MORPHOLOGICAL FEATURES. I: GLIOMAS

Summary In‐vivo cell kinetics study following peroperative intravenous infusion of bromodeoxyuridine (BrdU) was done in 10 cases of primitive neuroectodermal tumors (PNET) and 44 nonglial tumors of different histological types. The histological features usually regarded as indicators of aggressive behaviour were examined in these tumors and correlated with in‐vivo labelling index (LI). In the case of meningiomas, increased cellularity, pleomorphism and mitosis had no correlation with LI. Benign non‐recurrent meningiomas usually showed Ll≤1% (mean 0.6 ±0.3%) whereas recurrent and malignant meningioma showed higher LI (mean 2.6 ± 0.5% and 2.8 ± 0.4% respectively). Follow‐up study suggested that meningiomas having benign histological appearance with LI > 1% might have increased chance of recurrence. In cases of PNETs among different histological features, mitosis and differentiation seemed to be related to the biological behaviour. Astrocytic differentiation was associated with lower rate of proliferation. In pituitary adenomas different hormone producing and null cell adenomas showed similar low proliferative potential (0.6 ± 0.3%). Benign nerve sheath tumors, craniopharyngioma and choroid plexus papilloma showed low in‐vivo LI of less than 1%. Thus the present study revealed the inadequacies of routine histological examination in assessing the aggressiveness of the nonglial tumors, especially meningiomas. In‐vivo LI may be a good supplement to histological diagnosis as well as helping to assess the prognosis and accordingly the management of individual cases.

Pathology of rabies: a light- and electron-microscopical study with particular reference to the changes in cases with prolonged survival.

SummaryLight-and electron-microscopical studies were conducted on necropsy material from six cases of rabies encephalitis including three with the unusual feature of surviving for over 14 days as a result of intensive medical care. This included administration of antiviral agents and interferon inducers and prevention of hypoxia by intermittent positive pressure ventilation. In all these cases, typical Negri bodies were demonstrated. Inflammatory reaction was absent or minimal. Unlike the cases with short survival where Negri bodies were infrequently seen and restricted mostly to the hippocampus, in cases with prolonged survival, they were present in large number, widely distributed throughout the grey matter of the brain. The associated inflammatory reaction in these cases, however, did not keep pace with the increase in number of inclusion bodies. Peripheral neuritis was observed in two of these cases, which also showed myelitis involving the cervical region and inflammation of dorsal root ganglia. One of them showed necrosis and severe inflammation of the lower cervical sympathetic ganglion. An electron-microscopical study conducted in four cases showed three forms of the inclusion body in the cytoplasm of neurons.

COCKAYNE'S SYNDROME IN TWO SISTERS

Abstract. Srivastava, R. N., Gupta, P. C., Mayekar, G. and Roy, S. (Departments of Paediatrics, Neurology and Pathology, All India Institute of Medical Science, New Delhi, India). Cockaynes Syndrome in two sisters. Acta Paediatr Scand, 63 461, 1974.–Clinical and laboratory data in two sisters with Cockaynes syndrome are presented. Both had severe dwarfiim and mental retardation and the elder girl (11 years) had senile facies, optic atrophy and intracranial calcification. The serum cholesterol values were elevated. Peripheral neuropathy was found in both cases, evidenced by slow nerve conduction velocities. Examination of sural nerve biopsies showed focal demyelination with preservation of axis cylinders. These observations support the concept of Cockaynes syndrome being a leucodystrophy.