[Liposarcoma of the pancreas. Study of a case including ultrastructure].

The authors report a case of polymorphous liposarcoma situated in the pancreas. Ultrastructural study of proliferation demonstrated two cell contingents which appeared to represent stages of varied differentiation in the elaboration of adipose cells. The marked preponderance in the case studied of clear and little organised cells would appear to justify the histological classification of the polymorphous liposarcoma as a relatively undifferentiated tumour.

[Immunocytochemical similarities between basophilic and chromophobe pituitary adenomas. Light and electron microscopic study of 13 cases (author's transl)].

ACTH, beta MSH, beta LPH, beta endorpSin, leucine and methionine enkephalin activities were tested in four Cushing pituitary basophilic adenomas and nine "chromophobe" adenomas with immunoperoxidase methods. The antisera gave various positive reactions in both of these groups. ACTH, alpha MSH and enkephalins were predominant.

[Ultrastructural study of meningiothelial meningioma with 'hyaline inclusions' (author's transl)].

One case of meningiothelial meningioma with "hyaline inclusions" (colloid-bodies or pseudopsammomas) as noted by Cushing and Eisenhardt (1938) and by Kepes (1961-1975) is reported by light and electron microscopy. Two types of these structures, either homogeneous or polymorphic, surrounded by microvilli are described and regarded as signs of secretory differentiation of tumor cells. In addition to Kepes' description, the authors show, at high magnification, the polymorphic material including homogeneous component, lamellar structures, microvesicles and dense bodies.

Neoplastic transformation of hamster brain cells in vitro by polyoma virus.

The transformation of cultivated hamster brain cells by polyoma virus is reported. The transformed cell line contained polyoma virus-specific nuclear, surface and transplantation antigens. Subcutaneous and intracranial inoculations revealed high tumorigenicity of the cells.

Intracranial supratentorial cysts in children excluding tumor and parasitic cysts.

The intracranial, liquid-containing cysts in children (excluding tumor and parasitic cysts) are relatively frequent in neurosurgical practice. They raise several problems about their nosology, etiology, clinical and radiological diagnosis, and treatment which are analyzed in a series of 36 cases of supratentorial cysts. The most frequent clinical feature is increased head circumference (22 cases) followed by epileptic fits (18 cases), as well as mental and motor retardation (19 cases).

Giant axonal neuropathy. Involvement of peripheral nerve, myenteric plexus and extra-neuronal area.

A case of giant axonal neuropathy in a 8 years old child is reported by light and electron microscopy. Clinically, this case is strikingly similar to the rare previous reports and characterized by a distal neuropathy, CNS symptoms and tightly curled hair. Giant axons were found in the sural nerve but had been absent at the onset of the illness.

[Transformation, in vitro, of cerebral hamster cells by polyoma virus].

A cell line called HCxPy was obtained in vitro by transformation of dissociated hamster brain cell cultures by polyoma virus. The first foci of transformed cells became evident 90 to 120 days after viral infection. This cell line is now at the 46th passage.

[Surgical results in prolactin-secreting pituitary adenomas (a propos of 40 personal observations)].

The authors present a serie of 40 histologically verified prolactin secreting adenomas. Thirty-four women and six men were explored using the usual techniques and operated by the transphenoidal approach with biological follow-up 3, 6 and 12 months post-operatively. Results were a function of tumor size and invasive potential.

Granular cell myoblastoma.

Electron microscopic observations in three cases of granular cell myoblastoma revealed that this tumor is made up of two types of cells. 1) Granular cells grouped into nests, surrounded by a basement membrane, and displaying characteristic inclusions. Numerous processes were observed close to these cells, showing filamentous and microtubular components lying parallel to their axes.

[Cerebral hemangiopericytoma. Ultrastructural study of one case].

The authors report electron-microscopic observations upon a primitive cerebral haemangiopericytoma. The vascular appearance of the tumour is due to the presence of abundant extracellular material which has a structure like that of vascular basement membranes. The fact that the tumour cells are pericytes is confirmed by the existence of intracytoplasmic microfilaments of 60-80 A in diameter, sometimes gathered into osmiophilic aggregations and forming simple cellular junctions (zonulae adherentes).

[Immunologic blood-brain barrier in the polyoma virus--Syrian hamster system].

The authors report premilinary results of an experiment on permeability of the blood-brain barrier (BBB) to anti-tumor virus-induced immunological factors in the polyoma virus/Syrian Hamster system. The animals were protected by subcutaneous or intracranial injections with virus before challenge with polyoma virus transformed cells by both routes. BBB seemed to be permeable to the efferent part of the subcutaneously induced immune reaction.

[Niemann-Pick disease (Crocker's type C): ultrastructural study of a case (author's transl)].

The authors report electron microscopic findings in brain, bone marrow and liver biopsies in a case of juvenile Niemann-Pick disease (Crocker's type C). The diagnosis was supported by clinical data increase of blood sphingomyelin and vacuolated histiocytes in bone marrow and liver. Neurons and glial cells were filled with two types of cytosomes: classical multilamellar bodies and unusual pleiomorphic bodies.

Fine structure of intercellular junctions and blood vessels in medulloblastomas.

Six medulloblastomas were studied by electron microscopy. Two features were found which seem to be constant and essential characteristics of medulloblastoma. First, cell junctions are abundant between tumor cells.

[Ultrastructural study of a chordoma].

An ultrastructural study of a case of sacral chordoma is reported. The cell type was monomorphic. The epithelial nature and the secretory function of the tumour cells was obvious in view of their content of desmosomes and the presence of mucopolysaccharide in the ergastoplasm and in the extracellular space.

[Atypical juvenile neurolipidosis. Ultrastructural study of a cerebral biopsy].

Electron-microscopic findings on a brain biopsy in a 9-year-old male affected by juvenile lipidosis are reported. Two types of neuronal cytosomes were discribed: lamellar concentric bodies, resembling membranous cytoplasmic bodies, and polymorphous complex bodies, unit membrane bound including various material, mostly resembling lipofuscin. The same storage was found in glial and endothelial cells.

[Ultrastructural study of a Masson's "humid meningioma"].

The authors report the ultrastructural analysis of a Masson's humic meningioma. The tumor presents at the electronic microscopic examination every sign of secretive hyperactivity and does not show any degenerative characteristics. The existence of an important extracellular material rich in pre-collagenic fibres accounts for lacunar texture of this neoplasia at optic microscopic investigation; the role played by tumoral cells in the elaboration of the material is taken into account and seems to corroborate histogenic ecto-mesenchymatous theory of arachnoidal cells.