title: Histologic mimics of perineural invasion.
abstract: BACKGROUND
  Perineural invasion (PNI) by primary cutaneous cancers is an important adverse risk factor. Certain benign conditions may mimic microscopic PNI. Mohs surgery is being performed more frequently on smaller primary cutaneous malignancies. While PNI may be present in these cases, it is likely to be microscopic and asymptomatic, affecting as little as one cutaneous nerve branch.
  
  
  METHODS
  Review of the literature base regarding PNI as well as contribution of original findings.
  
  
  RESULTS
  Four benign entities that could easily be confused with microscopic PNI are presented.
  
  
  CONCLUSIONS
  At least four benign mimics of microscopic PNI exist, important in the differential diagnosis of microscopic PNI. Knowledge of these entities should help dermatopathologists to correctly distinguish them from PNI and avoid unnecessary additional treatment.
authors.affiliation: Skin Cancer Specialist, Inc., Sarasota, FL 34233, USA. mjdunnmd@hotmail.com
authors.forename: Martin
authors.initials: M
authors.lastname: Dunn
authors.forename: Michael B
authors.initials: MB
authors.lastname: Morgan
authors.forename: Trevor W
authors.initials: TW
authors.lastname: Beer
authors.forename: Karl T K
authors.initials: KT
authors.lastname: Chen
authors.forename: Scott M
authors.initials: SM
authors.lastname: Acker
mesh_terms: D003937:Diagnosis, Differential; D006801:Humans; D010525:Peripheral Nerves / Q000473:pathology*; D010523:Peripheral Nervous System Diseases / Q000473:pathology; D010524:Peripheral Nervous System Neoplasms / Q000556:secondary*; D012878:Skin Neoplasms / Q000473:pathology*