title: Clinicopathological characteristics and perineural invasion in adenoid cystic carcinoma: a systematic review.
abstract: BACKGROUND
  Adenoid cystic carcinoma is the most frequent malignant tumor of the submandibular gland and the minor salivary glands. It is a malignant neoplasm that, despite its slow growth, shows an unfavorable prognosis.
  
  
  OBJECTIVE
  The aim of this study was to perform a systematic review of the literature on Adenoid cystic carcinoma in the head and neck region and its clinicopathological characteristics, with emphasis on the perineural invasion capacity of the tumor.
  
  
  METHODS
  A systematic search of articles published between January 2000 and January 2014 was performed in the PubMed/MEDLINE, SciELO, Science Direct, and Scopus databases.
  
  
  RESULTS
  Nine articles were selected for this systematic review. These demonstrated that the female gender was more often affected and that malignant tumors showed a high rate of distant metastasis, recurrence, and a low survival rate. The presence of perineural invasion ranged from 29.4% to 62.5% and was associated with local tumor recurrence.
  
  
  CONCLUSIONS
  Adenoid cystic carcinoma is commonly characterized by the presence of pain, high rate of recurrence, metastasis, and a low survival rate. Reporting studies with patient follow-up is of utmost importance for a better clinical-pathological understanding and to improve the prognosis of this pathology.
authors.affiliation: Universidade Potiguar (UnP), Natal, RN, Brazil.
authors.forename: Afonso Nóbrega
authors.initials: AN
authors.lastname: Dantas
authors.affiliation: Universidade Potiguar (UnP), Natal, RN, Brazil.
authors.forename: Everton Freitas de
authors.initials: EF
authors.lastname: Morais
authors.affiliation: Universidade Potiguar (UnP), Natal, RN, Brazil.
authors.forename: Rômulo Augusto de Paiva
authors.initials: RA
authors.lastname: Macedo
authors.affiliation: Universidade Potiguar (UnP), Natal, RN, Brazil. Electronic address: joao-tinoco@hotmail.com.
authors.forename: João Maria de Lima
authors.initials: JM
authors.lastname: Tinôco
authors.affiliation: Universidade Potiguar (UnP), Natal, RN, Brazil; Universidade do Estado do Rio Grande do Norte (UERN), Natal, RN, Brazil; Liga Norte-Riogradense contra o Câncer, Natal, RN, Brazil; Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN, Brazil.
authors.forename: Maria de Lourdes Silva de Arruda
authors.initials: Mde L
authors.lastname: Morais
mesh_terms: D003528:Carcinoma, Adenoid Cystic / Q000473:pathology* / Q000556:secondary; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D009361:Neoplasm Invasiveness; D012468:Salivary Gland Neoplasms / Q000473:pathology*; D012470:Salivary Glands, Minor / Q000473:pathology*; D012737:Sex Factors; D015996:Survival Rate
keywords: Glândulas salivares; Mouth neoplasms; Neoplasias bucais; Neoplasias das glândulas salivares; Salivary gland neoplasms; Salivary glands