Osteochondroma of the L-5 vertebra: a rare cause of sciatic pain. Case report.

Solitary or multiple osteochondromas, which are benign bone tumors that usually occur in the long bones, are rarely found in the vertebral column. When present in the spine, however, they have a predilection for the cervical or upper thoracic regions. The authors present the case of a solitary osteochondroma arising from the left L-5 articular process that contributed to sciatica; complete cure was achieved following its removal. It is possible to speculate that the cartilage of secondary ossification centers can be the origin of aberrant islands of cartilaginous tissue that cause the osteochondroma to form. The more rapid the ossification process of these centers, the greater the probability that aberrant cartilage will form. Therefore, the fact that osteochondromas are more frequently located in the higher segments of the vertebral column could be explained by the different durations of the ossification processes in these centers, which increase gradually below the cervical segments.

Problems with post-clipping aneurysmal rests.

The postclipping aneurysmal rest is a uncommon but sometimes dangerous event, that is generally underestimated. We distinguish the aneurysmal rest on the basis of its morphology in: 1) partial neck, 2) whole neck, 3) partial neck + partial sac, 4) whole neck + partial sac; on the basis of the relationship with the clip in: 1) proximal, 2) distal, 3) proximal + distal; on the basis of its size in: 1) small (< 2 mm), 2) medium (2-4 mm), 3) large (> 4 mm). From the surgical point of view the aneurysmal rests in our opinion can be classified as unavoidable, avoidable and intentional. Then we analyze the literature data in regard to the possible evolution and the risk of the rest and emphasize the importance of intraoperative angiography which has shown itself to be useful in avoiding aneurysmal rests. There is no consensus of opinion with regard to the type of treatment of the aneurysmal rest. In our opinion the factors which must be considered when deciding on the surgical treatment of a rest are: the age of the patient, mode of presentation of the previous aneurysm, the expertise of the surgeon and the approaches and the techniques used in the first operation, clinical presentation of the rest and its evolution, the surgeon's experience and the possibility of endovascular therapy. Finally we analyze some of the technical aspects of re-operation in relation to the anatomical relationship among the parent artery, the rest and the old clip.

Preoperative embolization in surgical treatment of spinal thoracic dumbbell schwannoma. A case report.

Schwannoma is the most common intraspinal tumor, which at times goes out of spinal canal and spreads into the paraspinal tissue to produce a dumbbell configuration. A 58-year-old woman is reported, in whom a plain thorax X-rays accidentally disclosed a mass located in the posterior mediastinum. Computerized tomography (CT) revealed a dumbbell lesion, 4.5 cm in diameter, in the right rib-vertebral groove at the T9 level. Spinal angiography showed localization of Adamkievicz artery at the T10 level on the left side. The lesion appeared hypervascular and was embolized by particulate agents (Contour Emboli 150-250 mu) with reduction of its blush. A combined two-team (thoracic and neurosurgeon) approach permitted an uneventful removal of a schwannoma.

Surgical treatment of a cerebral mycotic aneurysm using the stereo-angiographic localizer.

The authors report a case of mycotic aneurysm surgically treated by means of the Suetens-Gybels-Vandermeulen angiographic localizer system. The major advantages of this technique are reported.

Chronic encapsulated intracerebral haematoma: pathogenetic and diagnostic considerations.

Two cases of chronic encapsulated intracerebral haematoma are reported. The patients presented with progressive neurological deficits. Computed tomography scan showed a roundish, intracerebral lesion, that revealed ring blush after contrast infusion, with mass effect. At operation a thick, fibrous, brownish capsule, containing clots in different states of formation, was removed. The hypothesis of capsule formation due to an exuberant proliferation of arachnoidal fibroblasts, is discussed. Differentiation between encapsulated intracerebral haematoma and other chronic intracerebral blood collections is considered mandatory for appropriate treatment.

Intraventricular craniopharyngioma. Clinical and surgical considerations.

The authors present two cases of craniopharyngioma wholly located within the cavity of the third ventricle. The rarity of this condition is outlined. In these cases the computed tomography is not always sufficient to determine the correct surgical approach; therefore the Authors stress the importance of the clinical findings.

"Primary" leptomeningeal dissemination of medulloblastoma. Report of an unusual case.

The Authors report the case of a 5-year-old boy medulloblastoma presenting with "primary" widespread diffusion in the subarachnoid spaces of the posterior fossa without true mass lesion. The diagnosis, suspected first on the basis of the computed tomography (CT) findings, was confirmed by cytological examination of the cerebrospinal fluid (CSF) and by surgery. The Authors analyse the peculiar clinical features (rapid and severe deterioration of general conditions, hyperacute course of the illness and fatal issue) and the morphological aspects of the tumor (CT and surgical findings). To our knowledge no case of "primary" dissemination of medulloblastoma was previously reported.

Intracerebral venous hemorrhage in "high-risk" carotid-cavernous fistula.

Intracerebral hematoma associated with carotid-cavernous fistula is a rare occurrence. Based on a review of the literature and on the analysis of personal observation, the authors define as "high-risk fistula" a carotid-cavernous fistula at risk of intracerebral hemorrhage. Characteristic features of these are computed tomography demonstration of parenchymal vermicular enhancement of brain vessels, and an angiographic pattern of dilated and tortuous cerebral veins. When an intracerebral hemorrhage occurs in a patient with carotid-cavernous fistula an early but phased and combined neuroradiological-neurosurgical approach is suggested as the best way to treat this life-threatening situation.