title: Perineural invasion in squamous cell carcinoma of the head and neck.
abstract: OBJECTIVE
  To determine if perineural invasion (PNI) of small nerves affects the outcome of patients with squamous cell carcinoma (SCC) of the upper aerodigestive tract.
  
  
  METHODS
  Retrospective clinicopathological study of patients with at least 2 years of follow-up and with negative margins and no prior, synchronous, or metachronous SCC.
  
  
  METHODS
  Academic otolaryngology department.
  
  
  METHODS
  One hundred forty-two patients who had SCC of the oral cavity, oropharynx and hypopharynx, or larynx resected between 1981 and 1991.
  
  
  METHODS
  Surgery with or without adjuvant therapy.
  
  
  METHODS
  Local recurrence was examined with respect to PNI, nerve diameter, and microvascular or microlymphatic invasion. Perineural invasion was correlated with lymph node metastasis, extracapsular spread, and survival.
  
  
  RESULTS
  Perineural invasion of nerves less than 1 mm in diameter was present in 74 patients, lymphatic invasion in 53, and vascular invasion in 9. Perineural invasion was significantly associated with local recurrence (23% for PNI vs 9% for no PNI; P=. 02), and disease-specific mortality (54% mortality for PNI vs 25% for no PNI; P<.001). With extralaryngeal tumors, PNI was associated with nodal metastasis (73% vs 46%; P=.03). Perineural invasion was not associated with extracapsular spread (P=.47). Microvascular invasion, lymphatic invasion, and nerve diameter were not significantly related to local recurrence.
  
  
  CONCLUSIONS
  Perineural invasion of small nerves is associated with an increased risk of local recurrence and cervical metastasis and is, independent of extracapsular spread, a predictor of survival for patients with SCC of the upper aerodigestive tract.
authors.affiliation: Department of Otolaryngology, University of Pittsburgh School of Medicine, PA 15213, USA.
authors.forename: J J
authors.initials: JJ
authors.lastname: Fagan
authors.forename: B
authors.initials: B
authors.lastname: Collins
authors.forename: L
authors.initials: L
authors.lastname: Barnes
authors.forename: F
authors.initials: F
authors.lastname: D'Amico
authors.forename: E N
authors.initials: EN
authors.lastname: Myers
authors.forename: J T
authors.initials: JT
authors.lastname: Johnson
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000473:pathology* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007822:Laryngeal Neoplasms / Q000473:pathology / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000473:pathology / Q000601:surgery; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local; D009960:Oropharynx; D010525:Peripheral Nerves / Q000473:pathology*; D010610:Pharyngeal Neoplasms / Q000473:pathology / Q000601:surgery; D012189:Retrospective Studies