Professional
Technical
IVT
NET G1
Grade 1 neuroendocrine tumor with low proliferation rate and indolent behavior, defined by specific histological criteria.
Full Definition
NET G1 represents the lowest grade category in the WHO classification system for neuroendocrine tumors, characterized by fewer than 2 mitoses per 10 high-power fields and/or Ki-67 proliferation index less than 3%. These well-differentiated tumors typically have indolent behavior with slow growth rates and better prognosis compared to higher-grade neuroendocrine neoplasms. The G1 designation applies to tumors with maintained neuroendocrine differentiation and organized histological architecture.
Usage
Usage note: Always include the proliferation index values when documenting grade to support the classification.
In Context
- "Histopathology confirmed a NET G1 with Ki-67 index of 1% and absence of mitotic activity." — Pathology report
- "The pancreatic NET G1 was managed conservatively with surveillance imaging given its indolent behavior." — Treatment planning document
Also known as
Grade 1 NET
low-grade NET
Contrasted with
NET G3
poorly differentiated NEC
Don't confuse with
NET G2
well-differentiated G2