Noriyoshi Kawamura

MRI of orbital schwannomas.

Abstract The literature on MRI of orbital schwannomas is limited. The appearances in three patients with an orbital schwannoma were reviewed. A superior orbitotomy through a subfrontal craniotomy revealed a schwannoma in all cases. MRI characteristics of very low signal on T 1-weighted images and homogeneous postcontrast enhancement may be helpful for differentiating schwannomas from other intraconal masses.

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.

Dorsum sellae meningioma mimicking pituitary macroadenoma: case report.

BACKGROUND A dorsum sellae meningioma is a rare occurrence. It is difficult to evaluate dorsum sellae meningiomas preoperatively from the viewpoint of neuroimaging. We report a rare case of dorsum sellae meningioma mimicking pituitary macroadenoma in a 73-year-old woman. CASE PRESENTATION The patient presented with bitemporal hemianopsia and panhypopituitarism. Magnetic resonance imaging demonstrated a bright, homogeneously enhancing intra- and suprasellar mass and a hypointense region in this mass, which was interpreted as a dorsum sellae. Transsphenoidal extirpation was used because of a suspicion of nonsecreting pituitary macroadenoma. Histopathologically, the tumor was diagnosed as a meningioma. Superselective external carotid angiography before the second surgery revealed that the mass was supplied by the left accessory middle meningeal artery and appeared to originate from dorsum sellae. After preoperative embolization, the patient developed hyponatremia. The tumor was subtotally removed via a transcranial route, and the attachment to the dorsum sellae was coagulated extensively. She did well after a second surgical procedure. CONCLUSION These radiologic findings may be useful in differentiating dorsum sellae meningioma from pituitary macroadenoma.

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

Role of 3D-TOF magnetic resonance angiography for intracranial meningioma

Three-dimensional (3D) time of flight (TOF) magnetic resonance angiography (MRA) was performed in 13 patients with intracranial meningioma. 3D-TOF unenhanced MRA depicted arterial displacement by tumour, and poorly demonstrated the sinuses, veins and tumour mass. The direct visualization of the venous abnormalities on 3D-TOF MRA was improved by the administration of contrast material. 3D-TOF enhanced MRA simultaneously depicted tumour enhancement, arterial and/or venous displacement, and dural sinus involvement by the tumour, all of which were in good agreement with findings on conventional cerebral angiography. However, MRA tended to poorly demonstrate the feeding arteries as compared to conventional angiography. Our results indicate that multiview 3D-TOF enhanced MRA non-invasively provides important information about the topographic relationship between tumour mass and the surrounding vasculature.