Atypical teratoid/rhabdoid tumor with 26-year overall survival: case report.

Atypical teratoid/rhabdoid tumor (AT/RT) is an aggressive embryonic brain tumor predominantly seen in young children. The authors report an unusual case of a fourth ventricle AT/RT in an infant who survived for 26 years. The tumor was resected when the patient was 6 months of age, and radiation therapy (40-Gy total dose) was performed thereafter. The patient was free from the disease for 26 years until a recurrent tumor was found in the spinal cord. The spinal cord neoplasm was a "collision tumor" with 2 components: benign schwannoma and recurrent AT/RT. The patient died of dissemination of the recurrent tumor 5 months after it was excised. This is the longest survival of a patient with AT/RT ever reported and indicates that long-term survival, more than 20 years, can be achieved in infantile-onset AT/RT. Despite intensive treatment, the prognosis for AT/RT is very poor, especially in children younger than 3 years of age. The benefits of upfront radiation therapy for AT/RT should be carefully assessed with respect to its inevitable toxicity in very young children. However, early upfront radiation therapy may be of therapeutic interest to prevent aggressive progression of the disease.

An aneurysm rupturing into a middle cranial fossa arachnoid cyst presenting as an intracystic hemorrhage.

We report a case of an aneurysm rupturing into an arachnoid cyst presenting as a confined intracystic hemorrhage. A 37-year-old man with a history of sporadic headaches for several years complained of a headache of several days' duration. Brain computed tomography and magnetic resonance imaging revealed a cystic lesion in the left side of the middle cranial fossa that included a 3-cm-diameter hematoma in the Sylvian fissure without extracystic hemorrhage. Left carotid artery angiography showed an internal carotid artery-posterior communicating artery (IC-PC) aneurysm and an anterior choroidal artery aneurysm. The cyst wall was excised, and the aneurysms were clipped. The bleeding point was the spot at which the IC-PC aneurysm entered the arachnoid cyst. Right oculomotor nerve palsy developed after surgery, but resolved after 3 months. To the best of our knowledge, this is the only fourth report to date in the literature of a confined aneurysm rupturing into an arachnoid cyst.

Spontaneous regression of an asymptomatic meningioma associated with discontinuation of progesterone agonist administration.

An 80-year-old male visited the hospital as an outpatient with a head injury sustained in a traffic accident. Brain computed tomography incidentally revealed a left frontal lobe tumor measuring 5 cm in a diameter. The patient had a history of taking chlormadinone acetate (a progesterone agonist) prescribed several years previously as treatment for benign prostatic hypertrophy. The tumor was seen as an isointense lesion on T(1)-weighted magnetic resonance (MR) images with enhancement by gadolinium, and as a heterogeneously hyperintense mass on T(2)-weighted MR images. The tentative diagnosis was left frontal meningioma attached to the sphenoid ridge or sphenoid plane. The patient was managed conservatively because of his advanced age and no symptoms or progression were observed during a 9-month follow-up period. The medication for benign prostatic hypertrophy was changed from chlormadinone acetate to naftopidil (an alpha-2-blocker) about 9 months after his first presentation. The patient presented again 2 years later complaining of dizziness. Computed tomography and MR imaging performed at this time revealed remarkable regression of the tumor. The signal intensity change with regression of the tumor on T(2)-weighted images was observed as a hypointense lesion. Thus, we wish to emphasize that treatment of meningiomas, especially those diagnosed incidentally, must be based on a thorough consideration of any history of hormonal therapy with prostate disease.

Microscopic measurement of the facial nerve root exit zone from central glial myelin to peripheral Schwann cell myelin.

OBJECT: The authors have attempted to define the exact borders of the root exit zone (RExZ) of the facial nerve, measure the distribution of myelin histologically, and examine the relationship between contact vessels and the RExZ. METHODS: Seventy-five facial nerves were obtained from brainstems excised from 44 adult patients at autopsy. The arteries and veins associated with the facial nerve were counted and measured. The facial nerves, associated vasculature, and adjoining portions of the brainstem were then removed en bloc. These tissues were serially sectioned and stained, and a photomicrograph of each section was obtained. The distribution of myelin on each section was measured from the upper edge of the supraolivary fossette, and the relationship between contact vessels and the RExZ examined. The lateral transitional zone of the facial nerve began 8 mm distal to the upper edge of the supraolivary fossette (root exit point [RExP]) and had a mean length of 1.9 mm. The root detachment point (RDP) of the facial nerve at the medial side was located very close to the beginning of the medial transitional zone. In more than 80% of the nerves that were examined, vascular structures compressed the central glial myelin of the nerve. CONCLUSIONS: The authors propose the use of the terms "RExP," "RDP," and "transitional zone," instead of RExZ, which cannot be well defined. The RDP appears to be a good landmark for use during microvascular decompression.