Harubumi Kasai

Neuronal and glial characteristics of central neurocytoma: electron microscopical analysis of two cases.

Abstract We have identified two central neurocytomas which contained cells co-expressing glial fibrillary acidic protein and synaptophysin defined by double-label immunostaining. Dual-positive cells were mostly polygonal in shape and with a morphological appearence similar to that of reactive astrocytes. This distinct morphology could be used to distinguish cells expressing glial fibrillary acidic protein from cells with round and clear cytoplasm which did not express glial fibrillary acidic protein and which composed the majority of the tumor. Samples containing polygonal cells were selected for electron microscopy from toluidine blue-stained semithin sections. Ultrastructural findings were similar in both neurocytomas, with both being composed predominantly of round cells with clear cytoplasm corresponding to the clear cells identified by light microscopy. Dense-core vesicles and clear vesicles were frequently observed in the cell processes. Apart from these clear cells, polygonal cells with electron-dense cytoplasm were noted. Paralleling the results of double immunostaining, these polygonal cells contained both dense-core vesicles and intermediate, presumably glial filaments. Microtubules and lipofuscin granules were also observed. These results suggest that cells expressing glial fibrillary acidic protein in central neurocytoma include tumor cells with both neuronal and glial characteristics.

Solitary myofibromatosis of the skull: a case report and review of literature.

Case reportWe present a case of solitary myofibromatosis of the skull in a 4-year-old girl. Surgery was performed and the final diagnosis of myofibromatosis was made histopathologically.DiscussionSolitary myofibromatosis of the skull is rare and we found approximately 20 reported cases in the English-language literature. We reviewed eight well-described cases.ConclusionNeuroradiologically, common features such as a lytic lesion with a sclerotic rim on roentgenogram and intra-diploic lesion with periosteal new bone formation both in the outer and inner table of the skull on computed assisted tomography are noticed.

A histopathological study of craniopharyngioma with special reference to its stroma and surrounding tissue

The numerous pathology reports on craniopharyngioma describe the classical features of squamous epithelium and keratin. Relatively little attention has been paid to its stroma and the surrounding tissue. We focused our observation on these two areas in a retrospective study of craniopharyngiomas in 36 operative cases and 5 autopsy cases. The tumor interdigitated with the brain and pituitary gland. At the interface, the brain was markedly gliotic with Rosenthal fibers simulating pilocytic astrocytoma. The tumor stroma had reactive changes and commonly showed cyst formation and calcification.

Observation of Psammoma Bodies in Cultured Meningiomas: Analysis of Three-Dimensional Structure Using Scanning and Transmission Electron Microscopy

In contrast to the inner structure, three-dimensional structure of psammona bodies in meningiomas is not well defined. This study examined three cultured meningiomas, in which surface observation of psammoma bodies might be easier than in the tumor tissues since influence of interposing connective tissue is minimized in tissue culture. Early culture revealed that psammoma bodies with frank calcification were suspended in the tissue culture medium, and so were they collected, centrifuged, and then processed for electron microscopy. Ultrastructurally, psammoma bodies were mostly spherical in shape and composed of a core of dense calcification and surrounding collagen fiber bundles. Apart from psammoma bodies, round bodies with concentric lamination like a transversely cut onion were frequently noted by light microscopy. These bodies were composed mainly of tangles of collagen fibers emerged from surrounding tumor cell processes. The results suggest that psammoma bodies in meningiomas arise in part from meningothelial whorls due to collagen production by tumor cells followed by obliteration and disappearance of tumor cell processes, although some of the alternative pathways for psammoma body formation proposed by other investigators cannot be ruled out by this study.

Abstracts of Oral Presentations

S OF ORAL PRESENTATIONS

A case of petrous bone myxoid chondrosarcoma associated with cerebellar hemorrhage

We report a rare case in which a myxoid chondrosarcoma originated from the petrous bone and invaded the cerebellar hemisphere with hemorrhage. Neuroimaging showed the characteristic feature of multiple small cysts along the solid tumor, and the cystic formation was confirmed as a mucoid secretion by Alcian blue staining and electron microscopic examination. This tumor recurred following partial removal and stereotaxic radiosurgery.