title: MYB expression: Potential role in separating adenoid cystic carcinoma (ACC) from pleomorphic adenoma (PA).
abstract: BACKGROUND
  Basaloid tumors of the salivary gland both benign and malignant comprise ACC, cellular PA, basal cell adenoma (BCA), and basal cell adenocarcinoma. Rendering a diagnosis given a limited biopsy or fine needle aspiration (FNA) sample proves challenging. Activation of MYB by gene fusion has been found in salivary gland ACCs; therefore we investigated the utility of MYB immunohistochemistry (IHC) as a tool for distinguishing ACCs from other basaloid neoplasms.
  
  
  METHODS
  We selected 48 cases of ACC (11 FNA blocks [CB]), 37 histologic resections [HR]), 74 PA (36 CB, 38 HR), and 18 BCA (7 CB, 11 HR). FNA CB showed 82% of ACCs (N = 9 of 11) as positive for MYB nuclear staining whereas 68% of ACCs (N = 25 of 37) were positive in HR.
  
  
  RESULTS
  All PA were negative for MYB nuclear staining in both CB (N = 0 of 36) and HR (N = 0 of 38). CB showed 29% of BCA (N = 2 of 7) as positive for MYB nuclear staining and 55% (N = 6 of 11) positive in HR. Both ACC and BCA showed significantly higher mean staining intensity than PA in both CB and HR (P < 0.0001). When comparing ACC and BCA, significantly higher mean staining intensity was observed in CB (P = 0.02382) but not in HR (P = 0.42952).
  
  
  CONCLUSIONS
  MYB nuclear staining may prove useful in separating ACC from PA and BCA, especially in limited cellular samples. Diagn. Cytopathol. 2016;44:799-804. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia. amoon3@emory.edu.
authors.forename: Andres
authors.initials: A
authors.lastname: Moon
authors.affiliation: Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Cohen
authors.affiliation: Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia.
authors.forename: Momin T
authors.initials: MT
authors.lastname: Siddiqui
mesh_terms: D008949:Adenoma, Pleomorphic / Q000145:classification / Q000378:metabolism / Q000473:pathology*; D014408:Biomarkers, Tumor / Q000378:metabolism*; D044963:Biopsy, Fine-Needle; D003528:Carcinoma, Adenoid Cystic / Q000145:classification / Q000378:metabolism / Q000473:pathology*; D003937:Diagnosis, Differential; D006801:Humans; D020626:Oncogene Proteins v-myb / Q000378:metabolism*; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor; D020626:Oncogene Proteins v-myb
keywords: MYB; adenoid cystic carcinoma; fine needle aspiration; pleomorphic adenoma