Features of the histological structure of congenital and acquired cranial hernias of the skull base

Chernikova Nadezhda Alekseevna, Ryzhova Marina Vladimirovna, Satanin Leonid Alexandrovich, Snigireva Galina Petrovna, Shelesko Elizaveta Vladimirovna, Sakharov Alexander Vladimirovich

Basal craniocerebral hernia is a rare pathology characterized by protrusion of the substance of the brain and its membranes through a defect in the base of the skull, which occurs as a congenital malformation or as a result of trauma or surgery. Objective: to analyze the clinical data of patients with basal meningoencephalocele and the results of histological examination to search for clinical and morphological correlations in patients with congenital and acquired craniocerebral hernias. Material and Methods: a retrospective analysis of a series of 34 patients aged 0 to 18 years with basal meningoencephalocele who underwent surgical treatment at the N.N. Burdenko in the period from 2008 to 2020, who underwent a histological examination. Patients were divided into two groups: group 1 - patients with congenital meningoencephalocele (19 cases - 55.9%), group 2 - patients with acquired meningoencephalocele (15 cases - 44.1%) Results: When comparing histological findings by etiology, there were regularities. According to the state of the nasal mucosa and submucosa in congenital meningocele, hypertrophied glands were more common (14–73.7% of cases) than in traumatic hernias (5–33.3% of cases) p=0.036. With traumatic hernias, bone fragments were observed in the preparations - 6 (40%) cases, which was not detected in congenital meningocele p=0.004. Differences in the state of the brain tissue were found in the groups: in congenital meningoencephalocele, glial hyperplasia was more common - 15 (78.9%) cases than in acquired meningocele - 1 (6.7%), p<0.001. In traumatic meningocele, biopsy specimens showed signs of cerebral detritus - 4 (26.7%) cases, which was not observed in congenital meningoencephalocele p=0.03. Conclusions: histological examination reveals specific manifestations characteristic of basal craniocerebral hernias of different pathogenesis. Congenital meningoencephaloceles are distinguished by the presence of glial hyperplasia in the preparations; in traumatic meningoencephaloceles, cerebral detritus is noted. Mucosal changes in congenital meningoencephalocele are due to the presence of a large number of glands, which is associated with the age of patients. With traumatic defects in the mucosa, bone fragments were more common, which may prevent the cessation of liquorrhea.

Keywords:Meningoencephalocele, encephalocele, meningocele, skull base, histological examination.