perineural invasion
Also written as: PNI — Perineural Invasion
Tumor growth along nerve pathways, indicating aggressive behavior and influencing treatment planning in surgical oncology.
Full Definition
Perineural invasion (PNI) describes the growth of cancer cells along nerve sheaths and within the perineural space. This finding is particularly significant in pancreatic, prostate, and head and neck cancers, where it correlates with poor prognosis, higher recurrence rates, and often explains patterns of tumor spread. PNI can be difficult to detect on imaging but is readily identified on histopathological examination. Its presence influences surgical planning, radiation field design, and overall treatment strategies, as tumors with PNI often require more aggressive multimodal therapy approaches.
Usage
Usage note: Often abbreviated as PNI; associated with neurological symptoms.
In Context
- "The pathology report confirmed perineural invasion, explaining the patient's preoperative pain symptoms." — histopathology findings
- "Extensive perineural invasion was noted, necessitating wider surgical margins and adjuvant radiation therapy." — treatment planning discussion