Hiromichi Yamazaki

Relationship between tissue polyamine levels and malignancy in primary brain tumors.

We studied the relationship between tissue polyamine levels and malignancy in 146 primary brain tumors. Astrocytoma showed a consistent rise in levels of N1-acetylspermidine (N1-AcSpd) in tissue with increased grade of malignancy. Furthermore, in astrocytoma, the patients whose tumors contained high levels of N1-AcSpd (> or = 15 nmol/g) in tissue showed a far worse prognosis, a significantly lower recurrence-free survival rate, and a shorter survival rate than did the patients whose tumors contained lower levels of N1-AcSpd (< 15 nmol/g). High-grade astrocytoma contained N1-AcSpd at the level of 15 nmol/g or higher, and most of the benign brain tumors, including low-grade astrocytoma, meningioma, pituitary adenoma, and normal brain tissues contained much lower levels of N1-AcSpd. However, medulloblastoma, hemangiopericytoma, and neurinoma showed an inverse correlation between N1-AcSpd levels in tissue and biological malignancy. These results suggest that levels of N1-AcSpd in tissue can be a promising biochemical marker of malignancy in astrocytoma. In the other primary brain tumors, however, the relationship between levels of N1-AcSpd in tissue and biological malignancy should be examined in each histopathological type.

Epidermoid tumors of Meckel's cave: case report and review of the literature.

Lesions of Meckels cave are extremely uncommon and difficult to diagnose. The symptoms and signs are variable, and the lesions may not appear on routine roentgenographic or computed tomographic examination. A patient with a small epidermoid tumor of Meckels cave that was diagnosed by magnetic resonance imaging is herein reported. The epidermoid appeared as a low-intensity mass on the T1-weighted image and as a high-intensity mass on the T2-weighted image. Coronal sections defined the anatomic relationship to the trigeminal nerve. Preoperative recordings of the trigeminal sensory evoked response may be predictive of postoperative recovery of neurological deficits. Furthermore, intraoperative recording was extremely useful in avoiding inadvertent neurological injury. Review of the literature confirms the rarity of this lesion and the usefulness of magnetic resonance imaging in diagnosing it, although based on a limited number of cases.

Recurrence of medulloblastoma 19 years after the initial diagnosis

Abstract A 25-year-old woman presented with recurrent medulloblastoma. She had been diagnosed with cerebellar medulloblastoma and treated for it at the age of 5 years. The new tumor was partially resected and chemotherapy was begun. However, a disseminated tumor of the spine was discovered and, despite radiotherapy, the patient became comatose and died. Histological examination of the tumor specimen showed characteristics similar to those of the first tumor. Late recurrence of medulloblastoma is rare, and a latency period of 19 years is the longest reported. This case violates Collins’ rule and exceeds other proposed periods of risk. Extension of the period of follow-up in patients with medulloblastoma is advocated.

The additive effect of alpha-difluoromethylornithine (DFMO) and radiation therapy on a rat glioma model.

SummaryThe effects of α-difluoromethylornithine (DFMO), radiation and the therapy of their combination were investigated in rats bearing G-XII glioma. DFMO treatment as well as radiation therapy prolonged the survival period when compared to the results in non-treated control rats. The combination therapy showed a greater effect on the survival rate than the single therapies, the effect being additive. The concentration of putrescine, spermidine, andN1-acetylspermidine in tumor tissues was lowered by DFMO, while that of spermine was slightly elevated. Radiation decreased the concentration of all the polyamines, putrescine, spermidine, spermine andN1-acetylspermidine. The concomitant treatment with DFMO and radiation further decreased the concentrations of putrescine andN1-acetylspermidine in tumor tissues. The survival period of glioma-bearing rats is inversely correlated with the tissue levels of putrescine plusN1-acetylspermidine.

Epidermoid Tumors of Meckelʼs Cave: Case Report and Review of the Literature

: Lesions of Meckels cave are extremely uncommon and difficult to diagnose. The symptoms and signs are variable, and the lesions may not appear on routine roentgenographic or computed tomographic examination. A patient with a small epidermoid tumor of Meckels cave that was diagnosed by magnetic resonance imaging is herein reported. The epidermoid appeared as a low-intensity mass on the T1-weighted image and as a high-intensity mass on the T2-weighted image. Coronal sections defined the anatomic relationship to the trigeminal nerve. Preoperative recordings of the trigeminal sensory evoked response may be predictive of postoperative recovery of neurological deficits. Furthermore, intraoperative recording was extremely useful in avoiding inadvertent neurological injury. Review of the literature confirms the rarity of this lesion and the usefulness of magnetic resonance imaging in diagnosing it, although based on a limited number of cases.

Subdural hemorrhagic injury after open heart surgery

We report two cases of acute subdural hematoma after cardiac surgery using cardiopulmonary bypass. In both patients, emergency removal and drainage of a subdural hematoma was performed by neurosurgeons, and complete recovery followed. Subdural hemorrhagic brain injury after cardiac surgery is rare and devastating; however, we consider early diagnosis and proper treatment to be effective because organic brain damage did not occur.

Subdural effusions in the posterior fossa associated with spontaneous intracranial hypotension

BACKGROUND Misdiagnosis of spontaneous intracranial hypotension remains a problem, despite increasing recognition. METHODS Three patients with spontaneous intracranial hypotension presented with typical findings on lumbar puncture, magnetic resonance (MR) imaging, and radioisotope cisternography. All patients showed subdural effusions in the posterior fossa on axial T2-weighted MR imaging. Axial MR images of 112 patients with other conditions were also screened for this finding. RESULTS One of three patients had typical orthostatic headache, and the other two had continuous headache. The finding of subdural effusions in the posterior fossa on axial T2-weighted MR imaging disappeared after treatment. Similar findings were found in 14 of 112 patients with other conditions. Most of the patients were over 60 years old or had dementia or previous radiation therapy. CONCLUSIONS Subdural effusions in the posterior fossa can be identified by T2-weighted axial MR imaging, and are useful for the diagnosis of spontaneous intracranial hypotension and for verifying the effectiveness of treatment.