title: The many faces of acinic cell carcinomas of the salivary glands: a study of 40 cases relating histological and immunohistological subtypes to clinical parameters and prognosis.
abstract: OBJECTIVE
  To study the morphological heterogeneity of acinic cell carcinoma (ACC) in correlation with clinicopathological parameters.
  
  
  RESULTS
  Forty well-characterized ACCs were classified as solid (n = 20), microcystic (n = 15), papillary-cystic (n = 4) or follicular (n = 1), based on the dominant architectural growth pattern. Fourteen tumours exhibited eosinophilic/clear cell morphology and 18 tumours were rich in zymogen granules (so-called blue dot tumours). High-grade morphology occurred in five tumours. Based on cytokeratin (CK) 7 staining and in analogy to CK7 expression in normal salivary gland epithelia, three distinct histogenetic subtypes were recognized: acinar (CK7-negative; n = 13), ductular (diffuse CK7-positive; n = 11) and mixed ductulo-acinar (10-66% CK7-positive cells; n = 16). Most papillary-cystic tumours displayed ductular differentiation (P = 0.015), whereas blue dot tumours never did (P < 0.001). Analysis of relapse-free survival (RFS) revealed that Stage I tumours had the best prognosis without any relapse in 18 years follow-up (P = 0.06). High-grade tumours were associated with shorter RFS (P = 0.028). Concerning the histogenetic types, monophasic (pure acinar or ductular) tumours were associated with a significantly better RFS than mixed ductulo-acinar tumours (P = 0.008).
  
  
  CONCLUSIONS
  The results underscore the great histological diversity of ACC, and the value of histogenetic subtyping as an additional prognostic factor regarding RFS.
authors.affiliation: Department of Pathology, University of Erlangen, Erlangen, Germany. stephan.schwarz@uk-erlangen.de
authors.forename: Stephan
authors.initials: S
authors.lastname: Schwarz
authors.forename: Johannes
authors.initials: J
authors.lastname: Zenk
authors.forename: Maximilian
authors.initials: M
authors.lastname: Müller
authors.forename: Tobias
authors.initials: T
authors.lastname: Ettl
authors.forename: Peter H
authors.initials: PH
authors.lastname: Wünsch
authors.forename: Arndt
authors.initials: A
authors.lastname: Hartmann
authors.forename: Abbas
authors.initials: A
authors.lastname: Agaimy
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis; D018267:Carcinoma, Acinar Cell / Q000378:metabolism* / Q000401:mortality / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012468:Salivary Gland Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology*; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor