Perineural Spread
Also written as: PNS — Perineural Spread
The macroscopic or radiologically demonstrable extension of tumour along a named nerve trunk, distinct from histological perineural invasion seen at the microscopic level in a tissue section.
Full Definition
Perineural spread (PNS), also called named nerve involvement or macroscopic perineural invasion, refers to the clinically and radiologically detectable extension of head and neck malignancy along major named nerves such as the inferior alveolar nerve, facial nerve branches, or trigeminal nerve divisions—as opposed to the microscopic finding of perineural invasion (PNI) seen within a routine histological section. In oral and maxillofacial oncology reports, distinguishing PNS from PNI is critical because PNS influences the radiation treatment field and confers worse prognosis. Editors must not use 'perineural spread' and 'perineural invasion' as synonyms; PNI is a microscopic finding on pathology, while PNS is a macro- or radiological finding on imaging or clinical examination. The abbreviations 'PNS' and 'PNI' must be expanded on first use and applied consistently.
Usage
Usage note: PNS ≠ PNI. Perineural spread is macroscopic/radiological; perineural invasion is microscopic/histological. Always expand both abbreviations on first use and apply each consistently.
In Context
- "MRI demonstrated perineural spread along V3 from the primary buccal carcinoma to the foramen ovale, necessitating inclusion of the skull base in the radiation target volume." — Multidisciplinary tumour board report
- "Editors must clearly distinguish 'perineural spread' (macroscopic/radiological) from 'perineural invasion' (microscopic/histological) and should query any manuscript that conflates the two terms." — Editorial quality note for head and neck oncology journals