Hemangioma calcificans--a benign epileptogenic lesion

Variations in structural protein expression and endothelial cell proliferation in relation to clinical manifestations of cerebral cavernous malformations

OBJECTIVE

Cerebral cavernous malformations (CCMs) are associated with hemorrhagic proliferation of endothelial-lined vascular caverns, resulting in hemorrhagic stroke, epilepsy, and other neurological manifestations. We hypothesize that structural protein expression and endothelial cell proliferation markers within CCM lesions are different in the setting of various clinical manifestations.

METHODS

The percentage of immunohistochemically stained caverns positive for collagen IV, fibronectin, laminin, alpha-smooth muscle actin, myosin, and smoothelin and the percentage of dividing endothelial cells within caverns were determined in 36 excised CCM surgical specimens. These were compared in CCMs with different multiplicity, location, and size in patients of different age, sex, seizure status, and hemorrhage status.

RESULTS

Comparisons of seven lesion features and clinical manifestations with the fraction of caverns containing the structural proteins studied and endothelial cell proliferation demonstrated no significant differences. A possible exception was the difference (P < 0.05) in the fraction (mean +/- standard deviation) of positively stained caverns for collagen IV between adult (0.63 +/- 0.39) and pediatric patients (0.87 +/- 0.21) as well as fewer caverns with laminin expression in older patients. These trends did not sustain significance with Bonferroni's correction for multiple comparisons.

CONCLUSION

The fraction of caverns containing the particular structural proteins studied and endothelial cell proliferation within caverns are not correlated with particular lesion features and clinical manifestations that were investigated in CCMs. The possible fewer fractions of caverns containing collagen IV and laminin in adult lesions compared with pediatric lesions may have implications for lesion regression and quiescence with age.

Intracranial cavernous malformations: lesion behavior and management strategies

Intracranial cavernous malformations are vascular anomalies consisting of endothelium-lined caverns filled with blood at various stages of thrombosis and organization and separated by a collagenous stroma devoid of mature vessel wall elements. They occur in an estimated 0.45 to 0.9% of the population, with male and female patients equally affected and all ages represented. They commonly manifest as seizures, gross intracranial hemorrhage, and focal neurological deficits. Lesions are frequently multiple in the same patient, and 10 to 30% are associated with familial clustering. Several reports have documented a dynamic clinical-radiological lesion behavior with de novo lesion genesis, intralesional and perilesional hemorrhage, and corresponding fluctuations in lesion size. Hemorrhagic risk and neurological disability seem to be related to multiple factors, including lesion location, age, gender, state of reproductive cycle, and previous hemorrhage. Lesions may behave aggressively with repetitive hemorrhages and cumulative disability or may remain quiescent for many years. Management strategies include expectant follow-up in patients with asymptomatic or inaccessible lesions, excision of symptomatic and accessible lesions, and radiosurgery of progressively symptomatic lesions in inoperable locations. Relevant disease-specific outcome parameters are proposed to guide clinical decisions and future research. Prospective, stratified, hypothesis-driven studies using rigorous epidemiological methods must be undertaken to delineate patient and lesion factors influencing clinical aggressiveness. Biological studies are essential to uncover strategies to predict and modify lesion behavior.

Remote epileptogenic focus detected by electrocorticogram in a case of cavernous angioma

In a case of cavernous angioma, a remote gyrus, which was found to contain an epileptogenic focus by intraoperative electrocorticography (ECoG), was resected simultaneously with lesionectomy. The patient was a 27-year-old male who was referred to our hospital because of frequent systemic tonic-clonic convulsions. ECoG revealed an epileptogenic focus not only in the cortex around the angioma-affected tissue of the left frontal lobe but also in an angioma-free remote gyrus. These epileptogenic foci were removed in addition to lesionectomy. The postoperative course was uneventful. Now (two years after surgery), the patient is seizure-free without any anti-convulsive agent. In the surgical treatment of convulsions-accompanied by cavernous angioma, it is essential not only to detect epileptogenic foci by intraoperative ECoG but also to remove these foci together with the angioma.

The epileptic focus versus the pathological focus

The relationship between the epileptic focus and the causative lesion has been studied to define when resection of the epileptic focus may be associated with removal of the lesion. Experimental studies reveal that a maturation phase is followed by a progressive autonomisation of the epileptic focus from the induced lesion. Thereafter there may be a progressive course to such experimental epilepsy with spreading of the epileptic lesions and possible creation of a secondary focus. However, in man the findings are less coherent and sometimes contradictory. In long term intractable epilepsy, simple removal of the causative lesion can be effective. A hypothesis is proposed to explain these phenomena--the hypothesis of systemic focal epileptogenesis. It is further proposed that endogenous excitotoxic agents such an quinolinic acid may have effects on the epileptic focus only when the causative lesion is present producing a subtle modification of the blood brain barrier.

Clinical, radiological, and pathological spectrum of angiographically occult intracranial vascular malformations. Analysis of 21 cases and review of the literature

The clinical, radiological, and histopathological features of 21 cases of angiographically occult intracranial vascular malformations (AOIVM's) are analyzed, and a review of 241 additional appropriately documented, histologically verified cases collected from the literature is presented. In all, there were 115 (43.8%) arteriovenous malformations, 82 (31.2%) cavernous angiomas, 26 (9.9%) venous angiomas, 10 (3.8%) cases of capillary telangiectasis, and 29 (11%) mixed or unclassified angiomas. The result of the analysis shows that there are no essential differences in the patterns of clinical presentation, the computerized tomography (CT) appearance, or the surgical prognosis among these pathological types of vascular malformations. Certain histological features common to all AOIVM's (such as the small caliber, the more or less complete thrombosis of the malformed vessels, and the changes induced in the surrounding brain tissue by repeated microhemorrhages) seem to determine the biological behavior of the anomaly rather than the predominant type of vessel involved. Thus, subdivision of AOIVM's into the four classical pathological types has little practical value. Most AOIVM's are visualized by the CT scan and show a rather typical appearance. Surgical removal, which prevents rebleeding and ameliorates or suppresses seizure activity, is usually easy to perform and represents the treatment of choice for patients with clinically symptomatic AOIVM's.

An unusual fibro-osseous lesion of the brain. Case report

An unusual case is described of a fibro-osseous lesion of the brain. Some other causes of densely calcified intracranial lesions are briefly discussed.

Hemangioma calcificans with circumscribed brain atrophy

A case of hemangioma calcificans is presented. On CT scan, the tumor shows no mass effect but is accompanied by circumscribed low density which is deemed to indicate brain atrophy and an enlarged subarachnoid space. A case of this tumor surrounded by peritumoral brain atrophy has not been reported before.

Hemangioma calcificans. Case report

A 44-year-old woman presented with intraventricular hemorrhage and a calcified avascular mass lesion in the anterior third ventricle. This lesion proved to be a densely calcified variant of cavernous hemangioma, namely, hemangioma calcificans. Twelve previous cases of this lesion have been reported in the neurosurgical literature. Association with spontaneous intraventricular hemorrhage has not been previously reported. The clinical presentation, radiological appearance, surgical findings, and histopathology of this lesion are discussed and a brief review of the literature is presented.

Brain-stem hemangioma calcificans. Case report

A case of brain-stem hemangioma calcificans is described. The few cases reported in the literature prove the rarity of this tumor, which is considered a benign variant of cerebral cavernous hemangioma. Diagnosis and treatment of these tumors are briefly discussed with a review of the literature including 11 previous cases.