Medulloblastoma

Medulloblastioma is a malignant brain tumor of oligodendroglial elements of the third ventricle—uniform astrocytes with a desmoplastic reaction. The most common localization is the III, IV ventricles and the foramen magnum; rarely, tumors can occur in the area of ​​the cerebellar infundibulum and the pons. Small tumors are multiple, have a tortuous course, large multiple tumors are located concentrically, and occupy most of the third ventricle. Central necrosis is often observed, infiltrating the cavity of the third ventricle, around which the tumor has the form of a ring, and its inner surface can form a continuation of the inner surface of the 3rd ventricle (on a section of the gray matter of the brain, a dark background is visualized at the border between adjacent zones - Bumke’s sign, characteristic of lesions of the third ventricle). Large neoplasms due to compression of the bottom of the third ventricle often protrude into the subarachnoid space (“sulfur sign”). Often there are also signs of a pronounced mass effect, causing both compression of the medulla and a local increase in cerebrospinal fluid pressure, which is manifested by the presence of congestive spots of various sizes on the thalamus. When performing cytological and histological examination of medullioblastomas, one should remember their complex and diverse tissue composition, since in some cases, when performing paraffin microscopy in biopsy specimens, one can observe

Medulloepithelioma or **medulloblastoma** is a malignant tumor of the cerebellum and fourth ventricle localized in the fundus of the latter. This is a type of brain tumor.

*Medulloblastma* is a tumor of primitive origin, mainly observed in children aged 15-35 years. The peak incidence is recorded from 5 to 12 years. The epithelial origin causes the rapid development of metastases in the liver, lungs and mediastinum, as well as similarities with the metastatic process in the lymph nodes of the neck. Despite the fact that the tumor tissue is located in the brain structures, when localized in the occipital lobes, the tumor is often detected after examining the head in the forehead, eyes and nose. The cerebellar hemisphere is most often affected.

The tumor grows slowly. Only with large sizes is pressure felt on nearby organs. Patients complain of headaches, drowsiness, fatigue, poor coordination of movements, and a tendency to faint. In some cases, memory deterioration is observed in the absence of neurological symptoms. But such symptoms do not occur in all patients and not always in the early stages. One of the leading clinical features of medulloblastiomo is the increase in headache as the size increases.