A 61-year-old female developed subarachnoid hemorrhage after trans-sphenoidal surgery for Rathke's cleft cyst. Neuroradiological examination revealed a large aneurysm at the C₁ portion of the right in ternal carotid artery. Autopsy revealed marked proliferation of aspergillus hyphae in the wall of the aneurysm. A review of previously reported cases of fungal aneurysm proposes two developmental processes. Aneurysms secondary to fungal meningitis tend to be large in size and located in the ma jor cerebral artery trunk, but aneurysms following fungal sepsis tend to be small and in peripheral branches. The former aneurysms are probably caused by fungus invasion into the intracranium , usually from the paranasal sinus, and the latter may be due to fungal emboli like bacterial emboli in bacterial endocarditis.Ruptured fungal aneurysms are difficult to treat, so fungal meningitis or sepsis must be eradicated before an aneurysm develops.

Mirroring the ambiguities noted with other endocrine tumours, histology is a poor predictor of the invasiveness of pituitary adenomas. Accordingly, the proteins p27Kip1 (p27) and Ki-67, which respectively block cell-cycle progression and reflect proliferative activity of cells, were studied immunohistochemically in 123 specimens of pituitary adenomas including 57 clinically verified invasive cases. Only Ki-67 had a significant association with invasiveness; only p27 differed significantly between functioning and nonfunctioning adenomas, with a higher frequency of cell labelling in the former. No relationship between Ki-67 and p27 was obtained. Ki-67 detected by MIB-1 is thus an important marker related to the invasive potential of adenomas, and thereby may be helpful in planning postoperative management of patients with pituitary adenomas.

The occurrence of a totally suprasellar ectopic pituitary adenoma in a 71-year-old man is described. The tumor was attached to the pituitary stalk, extending upward toward the third ventricle. No intrasellar lesion was observed. Histological examination revealed a pituitary adenoma with large numbers of eosinophilic cells with moderate nuclear polymorphism and rare mitosis. Immunohistochemical staining revealed that the tumor cells were strongly positive for anti-adrenocorticotropic hormone antibody. A review of five previously reported intracranial ectopic pituitary adenomas revealed that two were silent corticotropic tumors and two occurred with Cushing's syndrome.

Twenty-five patients with tumors of the central nervous system received bromodeoxyuridine (BUdR), 200 mg/sq m, by intravenous infusion every 8 hours for 3 days before surgery. Excised tumor specimens were fixed in chilled 70% ethanol, embedded in paraffin, and cut into 6-micron sections. Each section was reacted with monoclonal antibodies against BUdR and stained with immunoperoxidase to identify nuclei that had incorporated BUdR. The growth fraction of each tumor was estimated by calculating the ratio of BUdR-positive nuclei to the total number of tumor cells in three to six microscopic fields in viable areas of the tumor. In seven cases, the tumor doubling time was measured from the serial computerized tomography scans and an attempt was made to estimate the cell cycle time. The growth fractions ranged from 9.1% to 46.5% in malignant gliomas, 2.0% to 6.7% in low-grade gliomas, 11.2% to 43.2% in metastatic brain tumors, 0.8% to 1.9% in pituitary adenomas, 3.9% to 4.6% in acoustic neurinomas, and 6.2% to 8.2% in meningiomas and cerebellar hemangioblastomas. The estimated cell cycle time was 5 to 12 days in most malignant gliomas and brain metastases; however, the actual cell cycle time should be substantially shorter because cell loss was not considered in the calculation. Although the growth fraction appeared to correlate with the biological malignancy of each tumor, the tumor doubling time did not reflect growth potential. It is possible that unpredictable cell loss plays an important role in tumor growth at certain sizes. Therefore, the cell cycle times calculated in this study are considerably overestimated and should be interpreted with caution.