No abstract

The clinical and pathological features of six patients with so-called "intraventricular oligodendroglioma" are reported. The tumor had no predilection for sex, and the patients' age at diagnosis ranged from 15 to 39 years. The lesions were located in the lateral and/or third ventricles. Total removal of the tumor was performed in three patients, and the remaining three underwent partial resection. Postoperative irradiation was given to five patients. A follow-up study revealed that five patients were free of recurrent tumor at 15 to 227 months after treatment, and one was alive with disease 25 months after surgery. Histologically, all tumors were composed of small uniform cells, with perinuclear halos and regular round nuclei. Tumor cells were sometimes arranged around nucleus-free fibrillary zones. Mitoses were infrequent. Ultrastructurally, neoplastic cells had round nuclei with dispersed heterochromatin and organelle-sparse cytoplasm containing occasional microtubules, 20 to 25 nm in diameter, and scattered dense-core vesicles, 100 to 200 nm in diameter. Cell processes containing dense-core and clear vesicles were frequently present. Thus, these neoplasms should be considered neuronal in origin, and should be classified as "intraventricular neurocytomas."

Amyloid plaques are found in the brains of some patients with Creutzfeldt-Jakob disease (CJD) and all patients with a related transmissible disorder, Gerstmann-Sträussler syndrome (GSS). In scrapie, a prion disease of animals, amyloid plaques have been shown to be composed of prion proteins (PrP), which form filaments of relatively uniform diameter. We report here that antisera raised against hamster scrapie PrP specifically stain amyloid plaques in the brains of both humans and rodents with CJD as well as a human subject with GSS. Earlier studies showed that these antibodies react with both rodent and human CJD PrP. The immunostained congophilic amyloid plaques in rodent brains measured 10 to 30 micron in diameter and exhibited a Maltese cross appearance. Limited proteolysis enhanced immunostaining of amyloid plaques in human brain sections from patients with CJD or GSS. Presumably proteolysis increases the exposure of those epitopes shared by human and rodent PrP. The differences in immunoreactivity between rodent and human amyloid plaques are consistent with other findings showing that cellular genes, not infectious purified prions, encode PrP.

Three cases of patients with unusual neuronal tumors in the cerebral hemisphere are reported. All were associated with long‐standing epileptic seizures. Computed tomography disclosed low‐density lesions without contrast enhancement, which were interpreted as either arachnoid cysts or a cerebral infarction at initial diagnosis. Magnetic resonance imaging scans, however, revealed the lesions to be solid tumors. At surgery, the tumors were found to be relatively well demarcated, soft, and gelatinous. Histologically, all tumors were composed of small uniform stellate cells, which proliferated in a loose myxoid fibrillary matrix and resembled either oligodendroglial or astrocytic tumors. Ultrastructurally, however, all tumors showed neuronal differentiation, including numerous clear and occasional dense‐core vesicles, microtubules, and a number of synapses. A review of the literature uncovered no other such cases, and therefore it was decided to classify these tumors as a distinct group of benign neuronal tumors, designated as “cerebral” neurocytoma compared with “intra‐ventricular” neurocytoma. Related nosologic problems of neuronal tumors of the central nervous system and their possible histogenesis are also discussed. Cancer 1992; 70:529–537.

The development of neoplasms subsequent to therapeutic cranial irradiation is a rare but serious and potentially fatal complication. In this study, we retrospectively reviewed the clinical and pathological aspects of 11 patients who underwent cranial irradiation (range, 24-110 cGy) to treat their primary disease and thereafter developed secondary tumours within a span of 13 years. All tumours arose within the previous radiation fields, and satisfied the widely used criteria for the definition of radiation-induced neoplasms. There was no sex predominance (M: 5, F: 6) and the patients tended to be young at irradiation (1.3-42 years; median age: 22 years). The median latency period before the detection of the secondary tumour was 14.5 years (range: 6.5-24 years). Meningiomas developed in 5 patients, sarcomas in 4, and malignant gliomas in 2. A pre-operative diagnosis of a secondary tumour was correctly obtained in 10 patients based on the neuro-imaging as well as nuclear medicine findings. All patients underwent a surgical removal of the secondary tumour, 3 underwent additional chemotherapy, and one received stereotactic secondary irradiation therapy. During a median of 2 years of follow-up review after the diagnosis of a secondary tumour, 3 patients died related to the secondary tumours (2 sarcomas, 1 glioblastoma), one died of a recurrent primary glioma, while the remaining 7 have been alive for from 10 months to 12 years after being treated for the secondary tumours (median: 3 years). Based on these data, the clinicopathological characteristics and possible role of treatment for secondary tumours are briefly discussed.