Histopathology (histology)

What it is

Histopathology (or histology) is the examination of tumor tissue under a microscope by a pathologist. For gliomas, it is a foundational diagnostic step, allowing the tumor's cell type, appearance, and features of aggressiveness to be assessed.

Understanding Histopathology (histology)

After tissue is obtained (by biopsy or surgery), a pathologist examines thin, stained sections under the microscope. They evaluate what cell type the tumor resembles (for example, astrocytes or oligodendrocytes), how abnormal the cells look, how rapidly they are dividing, and whether aggressive features such as microvascular proliferation (abnormal blood vessels) or necrosis (dead tumor tissue) are present. These findings inform the tumor type and grade. In modern practice, histopathology is combined with molecular (genetic) testing to reach an "integrated diagnosis" that is more precise than either alone. Histopathology remains essential, providing the tissue-level picture that, together with molecular results, defines the glioma. Understanding histopathology clarifies the microscope-based foundation of glioma diagnosis.

Why it matters

Understanding histopathology helps patients and families see how examining the tumor tissue under a microscope forms the foundation of diagnosis — now combined with molecular testing to define the glioma precisely.