Masamitsu Abe

Dysembryoplastic neuroepithelial tumor: Report of three cases

BACKGROUND Dysembryoplastic neuroepithelial tumor (DNT) is one of the mixed neuronal-glial tumors that should be differentiated from low-grade gliomas. The recognition and correct diagnosis of DNT is important because this tumor is curable by excision. METHODS We report three cases of histologically proven DNTs with various image studies performed preoperatively and describe characteristic findings of them, as well as those of previous reports. RESULTS In our three cases, computed tomography (CT) showed a well-defined, nonenhancing hypodense area. Magnetic resonance imaging (MRI) demonstrated a cortical mass of hypointensity on T1- and of marked hyperintensity on T2-weighted images. I-123-IMP or Tc-99m-HMPAO single-photon emission computed tomography (SPECT) images showed marked hypoperfusion of the lesion. Thallium-SPECT showed no uptake. CONCLUSIONS I-123-IMP, Tc-99m-HMPAO, and Thallium-SPECT images, as well as CT and MRI, may be helpful in distinguishing DNT from low-grade gliomas.

Association of cerebral arteriovenous malformation with cerebral arterial fenestration

Abstract Cerebral arteriovenous malformations (AVMs) are rarely associated with other vascular lesions. Our goal was to examine the incidence of the coexistence of cerebral AVMs and cerebral arterial fenestrations. During the past 18 years, 51 patients with a cerebral AVM were examined with selective cerebral angiography in our institution. We retrospectively reviewed these cerebral angiographies and noted associated cerebral arterial fenestrations. We found five fenestrations distributed among 3 patients. In each patient one fenestration was located in the vertebral artery (VA). In 1 patient there were additional basilar and left middle cerebral artery fenestrations. Vertebral artery angiography was performed in 43 of the 51 patients; thus, the frequency of coexistence of AVM and VA fenestration was 7 % (3 of 43). Although the clinical significance may not be great, we found a noteworthy incidence of associated VA fenestrations in AVM cases.

Analysis of ischemic brain damage in cases of acute subdural hematomas

BACKGROUND Ischemic damage of the brain is one of the most important factors for the sequelae of acute subdural hematomas (ASDHs). However, ischemic damage is infrequently addressed in a systematic manner in the clinical setting. METHODS The analysis of ischemic brain damage was performed based on serial computed tomography (CT) scans in 80 patients with traumatic ASDHs. Single photon emission computed tomography (SPECT) for regional blood flow and/or magnetic resonance imaging (MRI) were also performed. RESULTS Follow-up CT scans showed ischemic brain damage in 19 patients and no significant damage in 35 patients. The remaining 26 patients progressively deteriorated to the point of brain death. The ischemic brain damage was seen most frequently in the territory of the anterior cerebral artery (13 cases), followed by the territory of the posterior cerebral artery (12 cases). The ischemic damages in the pallidum, the hypothalamus and the thalamus were demonstrated in 4, 8, and 4 cases, respectively. The ischemic damage in the underlying brain that was probably because of the direct compression of the hematoma was seen in only two cases. CONCLUSIONS Most of the ischemic brain damage noted in this study was because of arterial compression secondary to the brain shift and brain herniation, rather than the direct effect of the hematoma upon the underlying brain. Ischemic brain damage adversely affects outcome morbidity, and the difficulty in preventing ischemic damage in cases with marked brain shift leads to poor outcome in patients with ASDHs.

Autopsy report of primary CNS B-cell lymphoma indistinguishable from multiple sclerosis: diagnosis with the immunoglobulin gene rearrangements analysis

We report a case of primary CNS B-cell lymphoma indistinguishable from multiple sclerosis (MS). MRI of the head showed the spontaneous disappearance of the white matter lesions and the progressive cerebral atrophy. The brain biopsy failed to make a diagnosis of CNS lymphoma but rather suggested MS. Although the primary CNS lymphoma was suspected at autopsy, the immunohistochemical study showed the CNS-infiltrating lymphoid cells comprising both T-cells and B-cells. Analysis of the immunoglobulin and T-cell receptor gene rearrangements first provided evidence of primary CNS B-cell lymphoma.

Cerebral hemiatrophy caused by multiple developmental venous anomalies involving nearly the entire cerebral hemisphere.

The authors present a case of multiple developmental venous anomalies (DVAs) that involved nearly the entire cerebral hemisphere and that were diagnosed by magnetic resonance (MR) imaging and selective cerebral angiography. The ipsilateral cerebral hemisphere was mildly atrophic, and there were focal white matter lesions on the MR images. Angiography showed multiple DVAs involving nearly the entire right cerebral hemisphere. We suggest that longstanding venous congestion caused the atrophy and white matter lesions.

Frontal lobe tumor associated with late-onset seizure and psychosis: a case report.

Abstract: This is a report of a 55‐year‐old woman with a 6‐year history of uncontrollable complex partial seizure and severe delusion. A computed tomography (CT) brain scan showed a nonenhanced low density area with an ill‐defined mass located at the right frontal lobe. Magnetic resonance imaging (MRI) demonstrated an area of hyperintensity on T2‐weighted images. After a tumorectomy, the patient gradually recovered from the seizures and delusion. A histological diagnosis showed a mixed oligoastrocytoma or dysembryoplastic neuroepithelial tumor (DNT). The clinical and pathological features of the tumor as well as its relation to psychosis were discussed.

Ventricular diverticula in obstructive hydrocephalus secondary to tumor growth.

OBJECTIVEThe association of ventricular diverticula with intra- and paraventricular tumors causing obstructive hydrocephalus has rarely been reported. METHODSRecords and imaging findings for 57 patients with obstructive hydrocephalus caused by tumors who were treated at our institution were reviewed for the presence of ventricular diverticula. For the anatomic study of ventricular diverticula, data were collected from five cadaveric heads. RESULTSVentricular diverticula were identified on magnetic resonance imaging scans in five cases. Diverticula were similarly located in the quadrigeminal cistern but originated from the medial wall of the atrium of the lateral ventricle in three cases and from the superior portion of the fourth ventricle in two cases. Regression of diverticula occurred in all cases after either insertion of a shunt or removal of the obstructing tumor. The cadaveric study suggested that the choroidal fissure and the rostral portion of the superior medullary velum might be the origins of diverticula from the atrium and from the superior portion of the fourth ventricle, respectively. CONCLUSIONVentricular diverticula should be distinguished from other cystic lesions in the quadrigeminal region. Detection of an ostium of a diverticulum or communication between the cyst and the ventricular system is important for diagnosis.

Extremely tortuous superior cerebellar artery

Accepted: 16 December 2002 Published online: 4 February 2003

Thallium-201 SPECT of adjacent intracranial tumours : a contrast in thallium kinetics

Abstract We report a case of adjacent intracranial tumours: malignant fibrous histiocytoma (MFH) and meningioma. Thallium-201 single-photon emission computed tomography demonstrated different thallium kinetics between the tumours (slow washout from the MFH and rapid clearance in the meningioma) and could be said to have been useful for preoperative histological estimation.

Intradermal Dermoid Cyst Associated with Occult Spinal Dysraphism

A 2‐year‐old boy with congenital lumbosacral skin lesions is described. He presented with associated occult spina bifida and a sagittal cleft of the vertebral body deep in the skin lesions. The skin lesions presented as a combination of a lipoma, telangiectasia, mild hypertrichosis, and a dermoid cyst. Magnetic resonance imaging (MRI) revealed that the lipoma extended to the spina bifida region, but that it did not connect to the dura. MRI also demonstrated no other spinal lesions requiring surgical treatment. The intradermal location of the dermoid cyst observed in our patient was unusual. We discuss the location of dermoid cysts in the lumbosacral region associated with spinal dysraphism.