Risks and clinical implications of perineural invasion in T1-2 oral tongue squamous cell carcinoma.

Background Risks of perineural invasion (PNI) in T1-2 oral tongue squamous cell carcinoma (SCC) have not been specifically elucidated. Methods Pathological features, including PNI, were re-reviewed under regular hematoxylin-eosin staining in 190 patients with T1-2 oral tongue SCC. Results Tumor thickness >5 mm, PNI(+), and lymphovascular invasion (+) independently predicted lymph node involvement. PNI(+) and neck observation also independently predicted neck recurrence, but only PNI(+) was associated with a poor disease-specific survival (DSS; p = .003). In patients who were clinically node negative (cN0), elective neck dissection contributed to a better DSS in patients with PNI(+) tumors (p = .046), but not in patients with PNI (-) tumors (p = .809). Additionally, increased tumor thickness predicted the presence of PNI. Conclusion PNI is a crucial pathological feature for T1-2 oral tongue SCC. Elective neck dissection should be performed in patients who were cN0 with PNI. Careful evaluation for PNI should be advocated in regular pathological diagnosis. (c) 2011 Wiley Periodicals, Inc. Head Neck, 2012