Medulloblastoma
Overview
Plain-Language Overview
Medulloblastoma is a type of brain tumor that primarily affects the cerebellum, the part of the brain responsible for coordination and balance. It is most commonly diagnosed in children but can occur at any age. This tumor grows quickly and can cause symptoms like headaches, nausea, vomiting, and problems with walking or balance. Because it is located in the brain, it can affect many important functions and may spread to other parts of the nervous system. Early detection and treatment are important to manage symptoms and improve outcomes.
Clinical Definition
Medulloblastoma is a highly malignant primary central nervous system tumor arising from primitive neuroectodermal cells in the cerebellum. It is the most common malignant brain tumor in children and is classified as a WHO grade IV neoplasm. The tumor is characterized by rapid growth and a propensity for leptomeningeal spread through cerebrospinal fluid pathways. Molecular subgroups defined by distinct genetic alterations, such as WNT and SHH pathway mutations, influence prognosis and treatment response. Clinically, it presents with signs of increased intracranial pressure and cerebellar dysfunction. Histologically, it shows densely packed small blue cells with high mitotic activity and often exhibits Homer Wright rosettes.