Intermediate
Technical
IVT
circumscribed astrocytoma
Well-defined astrocytic tumor with distinct borders, contrasting with diffusely infiltrative astrocytomas.
Full Definition
Circumscribed astrocytoma refers to a group of astrocytic tumors characterized by well-defined borders and limited infiltrative capacity, in contrast to diffusely infiltrative astrocytomas. This category includes pilocytic astrocytoma, subependymal giant cell astrocytoma, and pleomorphic xanthoastrocytoma. These tumors typically have better prognoses than their diffuse counterparts and often present as discrete masses that can be completely resected. The circumscribed growth pattern is a key distinguishing feature in the WHO classification system.
Usage
Usage note: Use to distinguish from diffuse astrocytomas; specify subtype when known.
In Context
- "The imaging showed a circumscribed astrocytoma with minimal surrounding edema, suggesting complete resectability." — Radiology report
- "Histologically, this represents a circumscribed astrocytoma with piloid features consistent with pilocytic astrocytoma." — Neuropathology report
Also known as
well-circumscribed astrocytoma
localized astrocytoma
Contrasted with
diffuse astrocytoma
infiltrative astrocytoma
Don't confuse with
low-grade astrocytoma
focal astrocytoma