Citations

Abstract Three cases of large cerebral arteriovenous fistulae are presented in which surgical ablation was complicated by brain swelling from hyperperfusion breakthrough believed to be caused by acute intraoperative hypoperfusion superimposed on chronic preoperative hypoperfusion. On the basis of these cases, experimental data, and theoretical considerations, we seriously question the wisdom of using staged surgical resection of cerebral arteriovenous malformation to prevent complications related to alterations in cerebral hemodynamics. The reasons for this concern are: the repeated occurrence of acute-on-chronic hypoperfusion during staged resection; a lack of understanding of the time course for the correction of a disordered autoregulation; risk of hemorrhage between the initial and final resection; difficulty in assessing and substantiating flow reduction after subtotal resection; the rapidity of collateralization; the divergence of flow from large, readily accessible feeding arteries to deep penetrating vessels; and attenuation of the wall thickness in collateral vessels as a consequence of increased flow.

Abstract Radiation-induced meningiomas are becoming increasingly well-recognized. We report a case of a 35-year-old man who developed a suprasellar meningioma 9 years after receiving a radiation dose of 4480 cGy for a pituitary adenoma. The literature is also reviewed.

Abstract Eight surgical and one autopsy specimen of pituitary adenomas (six cases of Cushing's disease, two of Nelson's syndrome. and one of hypopituitarism) were studied by histochemical, immunohistocytological, and ultrastructural methods. Eight tumors showed the characteristic histochemical profile of corticotroph adenoma—amphophilic to basophilic, and periodic acid-Schiff-positive to some extent. In all tumors, immunohistochemical studies revealed adrenocorticotropic hormone (ACTH) and à-subunit in the cytoplasm of some adenoma cells. By electron microscopy, seven tumors were found to be monomorphous; six were typical corticotroph adenomas and one was a subtype II silent corticotroph adenoma. One unique lesion was bimorphous—i.e., composed of corticotrophs as well as cells resembling glycoprotein cells. Immunoelectron microscopy by the double-labeling immunogold technique, performed on one corticotroph adenoma, demonstrated the presence of ACTH and à-subunit not only within the same adenoma cells but also within the same secretory granules. The cytogenesis of ACTH à-subunit tumors, a rare form of plurihormonal adenoma. remains to be elucidated. The duration of disease associated with these tumors exceeded the duration in patients with ordinary corticotroph adenomas. Given the low frequency with which increases in serum à-subunit are detectable in patients with such tumors—13% in this series—hormone production is not recognized at preoperative evaluation.

Abstract The history of meningioma is reviewed, highlighting the personalities and events that shaped our understanding and management of this tumor. Early descriptions, nomenclature, and the history of surgical removal of meningioma are discussed and the important role of this tumor in the development of neurosurgery as a whole is stressed.

Abstract Fibromatoses are uncommon infiltrative lesions affecting musculoaponeurotic structures, most often of the limbs and trunk. Lesions involving the cranial cavity are rare and require the same aggressive surgical management as elsewhere in the body. This case illustrates their clinical and neuroradiological features and underscores the necessity for aggressive resection to avoid recurrence. The literature is reviewed. (Neurosurgery 29:123-126, 1991)

Abstract Neurofibromatosis is of particular interest to neurosurgeons because of the various central and peripheral nervous system tumors and, more rarely, cervicocerebral arterial lesions associated with the disease. In the present paper, we report two patients with neurofibromatosis Type 1 (von Recklinghausen's disease) who had anomalies of the extracranial vertebral arteries. A large extracranial vertebral artery' aneurysm was incidentally discovered in the first patient, a 43-year-old woman, after rupture of a subclavian artery aneurysm. The second patient, a 28-year-old woman, had an enlarging neck mass and was found to have an extensive extracranial vertebral artery arteriovenous fistula. The vascular lesions associated with neurofibromatosis Type 1 in general and those arising from the extracranial vertebral artery in particular are reviewed.

Abstract A unique gliomesenchymal neoplasm, consisting of a subependymoma, a form of low-grade glioma, and a rhabdomyosarcoma, is described. It arose and recurred in the brain stem of a 52-year-old man. Immunohistochemical studies demonstrated the presence of a neuroectodermal marker S-100 protein within some sarcoma cells. The occurrence of this rare tumor supports the concept that striated muscle may derive from a neuroectodermal precursor lesion.

Abstract Thirty patients with histologically confirmed posterior fossa ependymomas operated on between January 1976 and December 1988 were reviewed. The median age was 44 years (range, 1-69 yr). There were 7 children (aged 5 yr or younger) and 23 adults (aged 16 yr or older). There were 18 female patients and 12 male patients. Headache, nausea and vomiting, and disequilibrium were the most frequent symptoms. The most common findings were ataxia and nystagmus. Gross total resection was performed in 8 patients (27%), subtotal resection in 21 patients (70%), and biopsy in only 1 patient (3%), Tumors were low grade in 73% and high grade in 27%. Twenty-seven patients underwent posterior fossa radiotherapy (median dose, 5400 cGy). Fourteen patients also underwent spinal irradiation (median dose, 3520 cGy). Age was the only significant prognostic factor identified (P <0.01). The 5-year survival rates were 76% for adults and 14% for children. All 14 patients who died had recurrent or residual tumor at the primary site. This review suggests that in patients with primary posterior fossa ependymomas the following is true: 1) the young patient (5 yr old or younger) has a poor prognosis: 2) there was a trend toward a better 5-year survival rate with a gross total resection; 3) if recurrence occurs, it will be at the primary intracranial site; and 4) symptomatic spinal seeding does not occur frequently.

Abstract Two patients who had focal neurological deficits as the initial manifestation of a malignant non-Hodgkin's lymphoma involving the skull are described. Soft-tissue masses and variable bone destruction were the predominant computed tomographic findings, and magnetic resonance imaging studies revealed meningeal involvement in one case and sinus thrombosis in the other. Malignant non-Hodgkin's lymphomas initially appearing in the skull are rare, but these lesions should be considered in patients with a palpable scalp mass who have focal neurological signs.