Gemistocytic astrocytoma

Gemistocytic astrocytoma is a variant of diffuse astrocytoma, a type of brain tumor (glioma) that arises from astrocytes, the star-shaped glial cells that support neurons in the central nervous system. It is characterized by the predominance of gemistocytes — large, plump astrocytes with abundant eosinophilic cytoplasm and eccentric nuclei — comprising at least approximately 20% of the tumor cell population. Historically classified as a World Health Organization (WHO) grade II astrocytoma, gemistocytic astrocytoma is notable for its relatively higher tendency to progress to higher-grade malignancies (anaplastic astrocytoma or glioblastoma) compared to other diffuse astrocytoma subtypes. Under the revised WHO 2016 and 2021 classifications, these tumors are now further characterized by their IDH mutation status, which has significant prognostic implications. Gemistocytic astrocytomas primarily affect the cerebral hemispheres, though they can occur in other regions of the brain. Symptoms depend on tumor location and size and may include headaches, seizures, focal neurological deficits (such as weakness, speech difficulties, or visual changes), cognitive impairment, and personality changes. Increased intracranial pressure may cause nausea, vomiting, and papilledema. The disease predominantly affects adults, typically presenting in the third to fifth decades of life. Treatment generally follows the approach used for diffuse astrocytomas and includes maximal safe surgical resection when feasible, followed by radiation therapy and/or chemotherapy (commonly temozolomide), particularly in cases with unfavorable prognostic features or evidence of progression. Due to the recognized propensity for malignant transformation, close clinical and radiological surveillance is essential. Prognosis varies depending on factors such as IDH mutation status, extent of resection, patient age, and clinical performance status, but the gemistocytic variant is generally considered to carry a somewhat less favorable prognosis than other low-grade diffuse astrocytomas due to its higher rate of progression.

Common questions about Gemistocytic astrocytoma