tumor capsule
A distinct fibrous boundary that may surround certain brain tumors, facilitating complete surgical removal.
Full Definition
A well-defined fibrous or glial boundary that encapsulates certain types of brain tumors, creating a clear demarcation between tumor tissue and normal brain parenchyma. The presence of a tumor capsule is particularly characteristic of benign tumors such as meningiomas and some metastases, and significantly influences surgical approach and outcomes. Encapsulated tumors can often be removed completely through careful dissection along the capsular plane, minimizing damage to surrounding brain tissue. The capsule may be visualized intraoperatively and represents an important anatomical landmark for achieving gross total resection. However, not all brain tumors develop capsules, particularly infiltrative gliomas which lack clear boundaries.
Usage
Usage note: Should not be confused with 'pseudocapsule' which refers to compressed normal tissue rather than true fibrous encapsulation.
In Context
- "The well-defined tumor capsule allowed for complete removal without injury to adjacent brain tissue." — Operative note
- "Histological examination confirmed a true tumor capsule composed of compressed glial tissue." — Pathology report