Perineural invasion
In pathology, perineural invasion, abbreviated PNI, refers to cancer spreading to the space surrounding a nerve. It is common in head and neck cancer, prostate cancer and colorectal cancer.
Significance
Cancers with PNI usually have a poorer prognosis,[1] as PNI is thought to be indicative of perineural spread, which can make resection of malignant lesions more difficult.
Prostate cancer
In prostate cancer, PNI in needle biospies is poor prognosticator;[1] however, in prostatectomy specimens it is unclear whether it carries a worse prognosis.[2]
In one study, PNI was found in approximately 90% radical prostatectomy specimens and, PNI outside of the prostate, especially, was associated with a poorer prognosis.[3] However, there exists controversies about whether PNI has prognostic significance toward cancer malignancy.
Additional images
-
Perineural invasion prostate high mag.jpg
Micrograph demonstrating perineural invasion. HPS stain.
