[Morphology and clinical significance of the meningeal hemangiopericytoma (author's transl)]

Histogenesis of intracranial haemangiopericytoma and haemangioblastoma. An immunohistochemical study

An immunohistochemical study was performed on three meningeal haemangiopericytomas and four cerebellar haemangioblastomas (paraffin embedded) in an attempt to elucidate the uncertain histogenesis of these tumours. The tumour cells of all meningeal haemangiopericytomas show no expression of alpha-smooth muscle actin and, thus, no immunohistochemical proof of their true pericytic nature can be obtained. The stromal cells of cerebellar haemangioblastomas show foci of positive staining for S-100 protein, neuron-specific enolase and synaptophysin, thereby clearly indicating their neuroectodermal origin. These results allow the conclusion that the present nomenclature of these tumours is at least arguable and probably incorrect.

High activity iodine 125 endocurietherapy for recurrent skull base tumors

Experience with endocurietherapy of skull base tumors is reviewed. We present our cases of recurrent pituitary hemangiopericytoma, radiation-induced recurrent meningioma, recurrent clival chordoma, recurrent nasopharyngeal cancer involving the cavernous sinus, and recurrent parotid carcinoma of the skull base which were all successfully retreated with high-activity 125iodine (I-125) permanent implantation.

Multifocal spinal angiosarcoma after chordotomy

A male aged 60 is reported who, 5 years after chordotomy at the Th 2/3 level, developed acute paraplegia of the legs and a sensory transverse lesion due to an extradural tumour of the Th 1-4 level. Neuropathology revealed transverse necrosis of the thoracic spinal cord (Th 1-4) due to an intradural tumour at the upper thoracic and lumbar spinal levels, the thoracic malignancy arising at the site of the previous chordotomy, with a suture being observed within the tumour mass. Histology, positive immunostaining of tumour cells with Factor VIII antigen, a specific marker of endothelial cells and the ultrastructural demonstration of Weibel-Palade bodies in endothelial cells of the tumour vessels suggested a malignant mesenchymal tumour of angiosarcoma type presumably arising from the spinal meninges, and broadly invading the spinal cord. The usual relation of this extremely rare intraspinal vasoformative malignancy to previous chordotomy is discussed.