[Brainstem arachnoid cyst: case report and review]. / Arakhnoidal'naya kista stvola mozga: opisanie klinicheskogo sluchaya i obzor literatury.

There are no literature data on brainstem arachnoid cysts in humans. OBJECTIVE: To describe the clinical case of brainstem (pontomesencephalic) arachnoid cyst and to analyze classification, pathogenesis, differential diagnosis and treatment of this pathology considering literature data and own experience. MATERIAL AND METHODS: A 29-year-old patient with pontomesencephalic arachnoid cyst is reported. The disease manifested in childhood with a headache aggravated by bending and pushing. Later, syncope, vegetative-visceral paroxysms, mild oculomotor disturbances, transient paresthesia and numbness of the left half of the face occurred. Headaches became significantly more severe and resulted nausea and vomiting. Magnetic resonance imaging (MRI) revealed a two-chambered arachnoid cyst. A smaller chamber was localized in interpeduncular cistern, a larger one - in brainstem. RESULTS AND DISCUSSION: Differential diagnosis included cystic glioma and Virchow-Robin space enlargement. Fenestration of the cyst wall within interpeduncular cistern was performed via right-sided pterional approach. The diagnosis was verified by histological examination. The follow-up period was 14 months. We observed postoperative cyst reduction confirmed by MR data and regression of all symptoms except for minimal signs of medial longitudinal fasciculus dysfunction. CONCLUSION: Correct surgical approach for brainstem arachnoid cyst complicated by progressive neurological deterioration is confirmed by postoperative regression of cyst and symptoms.

[Glioblastoma in the region of previously resected meningioma. Case report and literature review]. / Glioblastoma, voznikshaya v oblasti udalennoi meningiomy. Klinicheskoe nablyudenie i obzor literatury.

Combination of meningioma and glioblastoma within the same anatomical region is casuistry. We found only 13 case reports in the available literature. Some of the authors reported induced nature of the second tumor, i.e. development under the influence of the primary neoplasm. We report a patient with glioblastoma of the right frontoparietotemporal region in 3 years after previous resection of benign right-sided meningioma of sphenoid wings. Mathematical analysis of the discovered pattern resulted conclusion about its random nature, i.e. no causal relationship between both neoplasms.