Hiromitsu Kurata

Germ cell tumors of the thalamus and the basal ganglia

Two cases of germ cell tumors (GCTs) of the basal ganglia are presented and 40 previously reported cases are reviewed. The incidence of GCTs of the basal ganglia and thalamus was estimated as less than 14% of all intracranial GCTs. All patients except for two (95%) were male, aged 7–19 years. The clinical course was usually slow. The major symptoms were hemiparesis, mental deterioration such as dementia or character change, precocious puberty, diabetes insipidus, oculomotor palsy, speech disturbance, and hemianopsia. Signs of intracranial hypertension did not occur until the late stages of the disease. The plain CT finding was characterized by an irregularly defined, slightly high-density area frequently accompanied by central low-density areas without significant mass effect. The tumors showed mild to moderate and nonhomogeneous contrast enhancement. An ipsilateral cerebral hemiatrophy was often found. MR images demonstrated the corresponding findings. GCTs of the basal ganglia had a high possibility of containing components other than germinoma such as choriocarcinoma, endodermal sinus tumor, and embryonal carcinoma. Thus, tumor markers in the serum, CSF, or cyst fluid were frequently positive. With recent refinement of microsurgical techniques as well as immunohistochemical study and measurements of tumor markers of serum, CSF, and cyst fluid, major resections of tumor, accurate pretreatment histologic diagnosis, and early determination of the specific types of this tumor appear to be readily possible. This is essential for effective treatment of patients not only with radiosensitive germinoma, but also those with radioinsensitive nongerminoma variants and a combination of them located in this region.

Cerebellar pilocytic astrocytoma with leptomeningeal dissemination: Case report

The authors present an extremely rare case of histologically benign cerebellar pilocytic astrocytoma that had already disseminated to the leptomeninges at the initial presentation.

Complete resection of a spinal meningioma extending from the foramen magnum to the second thoracic vertebral body via the anterior approach: case report.

The authors treated a patient with a huge, ventrally located spinal meningioma, extending from the foramen magnum to the second thoracic vertebral body. Vertebral body corpectomies were performed between the bottom of the second cervical vertebral body and the top of the first thoracic vertebral body, and the tumor was completely resected. Neurological symptoms and signs improved postoperatively.

Acrania: Report of the First Surviving Case

The first known surviving case of acrania is presented. The patient was the first child of a 29-year-old Japanese woman. Fetal ventriculomegaly was documented in the 35th gestational week. Prenatal sonography and magnetic resonance imaging suggested hydrocephalus with a wide encephalomeningocele. The baby was born at 38 weeks of gestational age by vaginal delivery. The patient had no calvarium, but did have a complete skull base with a partial defect in the occipital scalp and an underlying dural defect. Subsequently, the patient underwent repair of the scalp defect. At 3 months of age, after hydrocephalus developed, a subduro-peritoneal shunt was placed because of cosmetic and nursing problems. His developmental quotient was 10 at 3 years.

Minimally invasive retroperitoneal approach for lumbar corpectomy and reconstruction. Technical note.

The authors describe two occurrences of idiopathic spinal cord herniation, an entity that has been reported previously in only 11 cases. The patients described in this report presented in midlife with Brown-Séquard syndrome. Computerized tomography myelography and magnetic resonance (MR) imaging showed ventral displacement of the spinal cord with no apparent dorsal mass. Intraspinal cerebrospinal fluid (CSF) flow studies in which phase-contrast pulse sequence cine MR imaging was used displayed a normal pattern dorsal to the spinal cord. Percutaneous intrathecal endoscopic observation did not disclose dorsal intradural cysts, but ventral adhesions were seen between the spinal cord and the dura. Microsurgical intradural exploration revealed ventrolateral herniation of the cord and a ventral root through a dural defect into an epidural arachnoid cyst. The adhesions were released, the cord was repositioned intradurally, and the dural defect was patched. The patients showed gradual improvement postsurgery, as did most of the patients in the previously reported cases. The CSF flow and endoscopic studies were found to be particularly informative, and dural patching with surgical membrane is recommended.

Combined transpetrosal and fronto-orbito-zygomatic approach to a giant skull based meningioma: a case report.

BACKGROUND Recently, various surgical approaches to skull base lesions have been developed. Skillful use of the combination of two standard approaches make possible the removal of large brain lesions, which conventionally had been considered inoperative. In this study, we present a case of a giant meningioma located in the cerebellopontine angle and middle cranial fossa. A near total resection was achieved using a combined transpetrosal and fronto-orbito-zygomatic approach. CASE REPORT A 15-year-old boy presented with a meningioma that caused a left hearing loss, dysarthria, and cerebellar ataxia. Preoperative magnetic resonance imaging revealed a giant meningioma located in the right cerebellopontine angle, middle fossa, and cavernous sinus. The patient underwent a near total resection of the tumor through a combined transpetrosal and fronto-orbito-zygomatic approach. He experienced a marked improvement postoperatively and entered high school the following year. CONCLUSIONS An approach from several angles was necessary for the giant skull based tumor presented here. A combination approach was selected for obtaining a wide operative field with minimal brain compression during resection of neoplasm. According to the individual features of each case, selection of the operative approach, decisions regarding the extent of excision, and postoperative treatment regimens should be adequately planned in the preoperative period.