Hitoshi Izumiyama

Rathke's cleft cysts: differentiation from other cystic lesions in the pituitary fossa by use of single-shot fast spin-echo diffusion-weighted MR imaging.

SummaryObjective. Rathke’s cleft cysts are often difficult to differentiate from other sellar cystic lesions using conventional MR imaging. The purpose of this study was to investigate the usefulness of single-shot fast spin-echo (SSFSE) diffusion-weighted MR imaging (DWI) in the diagnosis of a Rathke’s cleft cyst. Pateients and Methods. We examined retrospectively 29 patients with a histologically verified sellar or suprasellar lesion containing a fluid component; 12 patients had a Rathke’s cleft cyst, 6 patients a craniopharyngioma, 5 patients a haemorrhagic pituitary adenoma, and 6 patients a cystic pituitary adenoma). Several regions of interest (ROIs) for apparent diffusion coefficient (ADC) measurements were identified in the fluid components of the lesions. For comparison, ADC values were normalized using a relative ADC (rADC), which was determined by dividing the ADC values of lesions by those of normal white matter and expressing the quotient as a ratio. Results. SSFSE provides diffusion-weighted images without significant susceptibility artifacts. DWI-SSFSE revealed Rathke’s cleft cysts as hypointense relative to the normal brain parenchyma in all cases. The mean value of ADC for Rathke’s cleft cysts was 2.12 × 10−3 mm2/sec. Both the ADC and relative ADC of the Rathke’s cleft cysts were significantly increased compared to those of the cystic components of craniopharyngiomas and haemorrhagic components of pituitary adenomas in the subacute phase (P < 0.05). There was not a statistically significant difference between Rathke’s cleft cysts and cystic components of pituitary adenomas (P < 0.05). Conclusions. DWI-SSFSE with ADC values provides objective information in the differential diagnosis of Rathke’s cleft cysts from other sellar cystic lesions. In addition, DWI-SSFSE with ADC values is useful for differentiating Rathke’s cleft cysts from craniopharyngiomas and haemorrhagic pituitary adenomas.

Considerations on surgical treatment for elderly patients with intracranial aneurysms

BACKGROUND The purpose of this study was to investigate why elderly patients have poorer outcomes and to determine indications for surgery in elderly patients. METHODS One hundred fifty-four patients with intracranial aneurysms admitted to the Department of Neurosurgery, Showa University School of Medicine, from 1990 through 1996 were reviewed. The patients were classified by age into three groups (young group, middle-aged group, elderly group). RESULTS Forty-four patients (28.6%) were in the elderly group (mean age, 73 years). No difference in outcome was found between middle-aged and elderly patients if patients were stratified according to clinical grade. In addition, the main factors related to unfavorable outcomes in elderly patients were infection, organ failure, aneurysm rerupture before operation, and delayed ischemic deterioration. Elderly patients were more likely to experience rebleeding and have poor outcomes. CONCLUSIONS Our results suggest that elderly patients should have early surgery. Furthermore, we found that the presence of hypertension or atherosclerosis had no significant effect on outcome. We conclude that early surgical treatment of aneurysms is indicated for elderly patients with good clinical grades in the absence of organ failure.

Early palliation of oculomotor nerve palsy following gamma knife radiosurgery for pituitary adenoma.

Introduction Isolated oculomotor nerve palsy is a very uncommon presentation of pituitary adenoma [1]. A decrease in the size of pituitary adenomas following radiosurgery has been documented in the literature [2–7]. To the best of our knowledge, an improvement in oculomotor nerve palsy following gamma knife radiosurgery has not been previously reported in patients with pituitary adenomas. We describe a 48-year-old female patient in whom oculomotor nerve palsy, which was caused by regrowth of an adrenocorticotropic hormone (ACTH)secreting pituitary adenoma, was ameliorated several days after gamFig. 1. Dynamic gadolinium-enhanced coronal T1-weighted MR image obtained at the time of presentation of left oculomotor nerve palsy revealing regrowth of an intraand suprasellar mass showing left CS extension or compression.

Silent mixed corticotroph and somatotroph macroadenomas presenting with pituitary apoplexy.

Abstract. We discuss three unique cases of pituitary macroadenoma presenting with pituitary hemorrhage but without typical endocrine symptomatology. Immunohistochemical analysis indicated positive reactivity for adrenocorticotropic hormone (ACTH) and growth hormone (GH), and in situ hybridization indicated the expression of proopiomelanocortin (POMC) and GH mRNA. We designated these cases silent mixed corticotroph and somatotroph adenoma. Patient 1 was a 30-year-old man, patient 2 was a 29-year-old woman, and patient 3 was a 59-year-old woman. All patients presented with a headache of sudden onset and visual disturbance. The patients did not exhibit typical Cushings or acromegalic features. Serum ACTH level was remarkably elevated in patient 1, and slightly elevated in patients 2 and 3. In all patients, serum GH levels were within normal range and magnetic resonance imaging revealed an intra- and suprasellar mass with pituitary hemorrhage. Transnasal pituitary surgery in the three patients disclosed a pituitary adenoma producing ACTH and GH. In patient 2, the residual adenoma reappeared along with an intratumoral hemorrhage, and was resected by secondary transnasal surgery. Silent mixed corticotroph and somatotroph adenomas are characterized by the following: no endocrine symptoms; presentation dominated by mass effect symptoms; macroadenoma presenting with acute pituitary hemorrhage; and production of both ACTH and GH.

Clinicopathological examination of glioma by proton magnetic resonance spectroscopy background

Automation of proton magnetic resonance spectroscopy (MRS) in recent years has made it possible for MRS measurement to be performed in a shorter time than before, and the number of reports of its usefulness for the assessment of glioma malignancy has been increasing in the past several years. We studied the efficacy of proton MRS when used for glioma and conducted clinicopathological examination of glioma. The subjects were 15 patients who had received a pathological diagnosis of glioma at our hospital (6 cases of glioblastoma, 1 case of anaplastic astrocytoma, 4 cases of low-grade astrocytoma, and 4 cases of radiation necrosis); Siemens Magnetom Vision 1.5T was used for the study. Regions of interest (ROIs) were defined as the areas where abnormal signals were found on magnetic resonance imaging (MRI). Areas of primary peaks, such as choline (Cho),N-acetylaspartate (NAA), and lactate (Lac), were measured, and the ratios to normal brain tissue were examined. This study revealed a tendency of increased malignancy of glioma with a decrease in NAA. Some cases also displayed a decrease in Cho with an increase in malignancy. Assessment of malignancy must not be based on a single ROI alone, but several ROIs should be assessed comprehensively. Measurement was difficult when the tumor volume was small. Because diagnosis of very early glioma by MRS seemed difficult, other adjunctive diagnoses may be necessary. Proton MRS is very useful for diagnosis of glioblastoma.

Usefulness of bone window CT images parallel to the transnasal surgical route for pituitary disorders.

Summary. Objective: Before operating on 130 patients with pituitary disorders, we evaluated their bone window CT images sliced parallel to the transnasal surgical route to assess the surgical anatomy of the nasal cavity for transnasal surgery. Methods: High resolution bone window CT was performed in 3- to 5-mm slices parallel to the imaginary line connecting the inferior margin of the piriform aperture and the top of the sellar floor, parallel to the transnasal surgical route. Results: This CT angle was useful in evaluating the width and depth of the operative field, the bony components of the nasal conchas, deviation of the nasal septum, the bony structure and mucosa in the sphenoid sinus, and the condition of the sellar floor. In patients requiring repeat surgery, the location of thin or thick nasal mucosa, residual bony septum, and inadequate sellar floor opening were easily detected. Conclusion: Bone window CT images sliced parallel to the transnasal surgical route provide direct visualization of the nasal anatomy for the transnasal approach. This method is helpful in determining how far to remove the sellar floor laterally, especially in cases requiring repeat surgery.

Histopathological and physiological characteristics of cultured human ACTH-secreting cells derived from a rapidly growing pituitary adenoma.

We observed the histopathological and physiological characteristics of adrenocorticotropic hormone (ACTH)-secreting adenoma cells derived from a rapidly growing pituitary adenoma, which have firm cell attachment and well-preserved hormonal function in a relatively longterm culture. Corticotrophs, obtained from a 43-year-old woman with Cushings disease in whom plasma ACTH levels increased in response to 1-deamino-8-D-arginine vasopressin (DDAVP) stimulation and the proliferative potential was very high, were grown in tissue culture for up to 6 months. The morphological features were observed by phase contrast and electron microscopy. The cultured cells were incubated with corticotroph-releasing hormone (CRH), arginine vasopressin (AVP), or DDAVP, and ACTH in the medium was measured by radioimmunoassay (RIA). The morphology of the ACTH-secreting adenoma cells in culture revealed a mixed population of formed clusters and spindle-shaped fibroblast-like cells. The adenoma cells were immunohistochemically positive only for ACTH. On electron microscopic observation, pituitary tumor cells obtained 6 days after seeding demonstrated many secretory granules, well-developed rough endoplasmic reticulum, and mitochondria; fewer secretory granules were observed after cultivation for 24 days. ACTH levels in the incubation media were elevated with stimulation by DDAVP, AVP, or CRH. In this study, the establishment of relatively longterm culture of human pituitary adenoma cells seemed to be due to the high proliferative potential of this adenoma. This in vitro study may imply that DDAVP as well as AVP directly stimulates ACTH release from corticotropic adenoma cells.

Haemorrhagic Nonsecreting Pituitary Adenoma Associated with Persistent Primitive Trigeminal Artery

A 44-year-old man presented with headache of sudden onset and visual disturbance. There was no personal or family history of neurological disease. Physical examination revealed decreased libido, pale skin, sparse axillary hair, and erection disorder. Neurological examination was normal except for a bitemporal hemianopsia. Endocrinological examination showed panhypopituitarism. A sellar tomogram showed an enlarged sella turcica. A computed tomographic (CT) scan revealed an iso-density mass with ring enhancement in the intraand suprasellar lesion. Magnetic resonance (MR) imaging demonstrated an intraand suprasellar mass with intratumoural haemorrhage, and a vascular structure arising from the left cavernous carotid artery (Fig. 1). No anomalous vascular structure in the pituitary fossa was observed on CT scan and MR imaging. Cerebral angiography showed a persistent primitive trigeminal artery (PPTA) from the left cavernous internal carotid artery which supplied the posterior cerebral arteries, bilaterally, superior cerebellar arteries, and the distal basilar artery (Fig. 2). This tumour was preoperatively diagnosed as a haemorrhagic nonsecreting pituitary adenoma. The patient underwent urgent transsphenoidal surgery. Tumour tissue in the haematoma was subtotally resected. The PPTA was not found in the pituitary fossa. Histological examination showed a di ̈use type chromophobic pituitary adenoma and immunohistochemical study revealed a null cell adenoma. The postoperative course was uneventful. Acta Neurochirurgica > Springer-Verlag 2000 Printed in Austria Acta Neurochir (Wien) (2000) 142: 1423±1424

Gliomatosis cerebri in a young patient showing various cranial nerve manifestations: a case report.

A case of gliomatosis cerebri in a 27-year-old man showing various cranial nerve manifestations is described. He was diagnosed as having cranial mononeuritis multiplex (bilateral oculomotor nerve paralysis, left facial nerve paralysis, bulbar palsy manifestations, and hypoglossal nerve paralysis) and was hospitalized in the neurology department on August 1, 2000. Although he continued to visit the neurology department after discharge, his manifestations showed no improvement. He was sent to our department for brain biopsy in August 2001. A biopsy performed at the Sylvian fissure from the frontal lobe/temporal lobe cortex showed high intensity on T2-weighted and Flair magnetic resonance imaging (MRI). The pathological findings were diffuse low-grade astrocytoma infiltrating between the pia mater and the cerebral cortex. We believed that the astrocytoma spreading on the subpia mater was responsible for the various cranial nerve manifestations, and we started whole-brain irradiation (46 Gy)+interferon (IFN)-β D.I.V. from September 2001. The pathological findings of the brain biopsy showed diffuse astrocytoma. The clinical presentation was dramatically improved after radiotherapy. It seemed that this tumor had spread along the subpia mater and subependyma. When he was discharged in early December, he walked by himself. The characteristic features of this case are that no lesion in the cerebellum or brain stem was found on MRI, even though the main manifestations were cerebello-brain stem manifestations, and biopsy of the cerebral cortex revealed astrocytoma. It should be noted that the clinical manifestations of astrocytoma in some cases are dissociated from the imaging observations.

Usefulness of gallium-67 scintigraphy in neurohypophyseal germinoma.

Summary The application of gallium-67 (67Ga) citrate has not been reported for the detection of an intracranial germinoma. The purpose of this report is to further evaluate the effectiveness of 67Ga scintigraphy in neurohypophyseal germinomas. 67Ga studies in five male patients with histologically verified intracranial pure germinomas were evaluated. Two germinomas were located in the neurohypophysis, two in the pineal region, and one in both the neurohypophysis and pineal region. The control group included 36 patients with histologically verified pituitary macro-adenomas. 67Ga study at the time of original diagnosis showed an abnormal accumulation in two neurohypophyseal germinomas, and negative accumulation in the other germinomas. In the two patients with neurohypophyseal germinomas, 67Ga study showed an abnormal accumulation in the intracranial tumour region in accordance with magnetic resonance (MR) findings. After postoperative irradiation or chemoradiotherapy, MR imaging and 67Ga studies revealed the complete disappearance of this tumour and no metastatic spread. In one of these two patients, a whole-body 67Ga study demonstrated multiple bone metastases one year later, and the reduction of these metastatic regions after chemotherapy. 67Ga study disclosed negative accumulation in all 36 pituitary macroadenomas. Although 67Ga uptake by neurohypophyseal germinomas may not be specific for this condition, this approach may provide some clues for diagnosing patients with neurohypophyseal germinomas.