title: High-grade transformation of acinic cell carcinoma: an inadequately treated entity?
abstract: OBJECTIVE
  Acinic cell carcinoma (AcCC) is an uncommon salivary gland malignancy. We aim to characterize the clinical and pathologic characteristics of AcCC with and without high-grade transformation (HGT). Importantly, cases of mammary analogue secretory carcinoma, a recently described histologic mimic of AcCC, have been excluded by using cytogenetics and molecular studies.
  
  
  METHODS
  Archival surgical pathology material was obtained for patients diagnosed with AcCC at Mayo Clinic Rochester between 1990 and 2010. Tumors harboring the ETV6-NTRK3 fusion transcript were excluded from analysis by using cytogenetics and molecular studies. Tumors with HGT were characterized by areas with an infiltrative growth pattern, nuclear anaplasia, prominent nucleoli, brisk mitotic activity, geographic necrosis, and stromal desmoplasia. Demographic and clinical data were extracted from the medical records.
  
  
  RESULTS
  AcCC with HGT was seen in 8 of 48 cases (17%). Patients with AcCC with HGT were significantly older than patients without HGT (median 69 vs 54 years; P = .04). Angiolymphatic invasion was more common in AcCC with HGT (P = .02). Relapse-free survival and overall survival were significantly worse for cases of AcCC with HGT (hazard ratio 10.4 and 9.3, respectively; P < .0001 for both comparisons). Locoregional recurrence-free survival was not significantly different (P = .12), but distant metastases-free survival was significantly worse in patients with HGT compared with non-HGT patients (P < .0001).
  
  
  CONCLUSIONS
  Prognosis for overall survival and distant relapse for AcCC patients with HGT is significantly worse than that for patients without HGT.
authors.affiliation: Division of Medical Oncology, Department of Oncology, Mayo Clinic Rochester, Rochester, MN, USA.
authors.forename: Ashish V
authors.initials: AV
authors.lastname: Chintakuntlawar
authors.affiliation: Department of Pathology, Immunology, and Laboratory Medicine, University of Florida College of Medicine, Gainesville, FL, USA.
authors.forename: Wonwoo
authors.initials: W
authors.lastname: Shon
authors.affiliation: Kailos Genetics, Inc., Huntsville, AL, USA.
authors.forename: Michele
authors.initials: M
authors.lastname: Erickson-Johnson
authors.affiliation: Department of Diagnostic Sciences, University of Pittsburgh School of Dental Medicine, Pittsburgh, PA, USA.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Bilodeau
authors.affiliation: Division of Biomedical Statistics and Informatics, Mayo Clinic Rochester, Rochester, MN, USA.
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Jenkins
authors.affiliation: Division of Anatomic Pathology, Department of Laboratory Medicine & Pathology, Mayo Clinic Rochester, Rochester, MN, USA.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Davidson
authors.affiliation: Division of Anatomic Pathology, Department of Laboratory Medicine & Pathology, Mayo Clinic Rochester, Rochester, MN, USA.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Keeney
authors.affiliation: Division of Anatomic Pathology, Department of Laboratory Medicine & Pathology, Mayo Clinic Rochester, Rochester, MN, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Rivera
authors.affiliation: Department of Otorhinolaryngology, Mayo Clinic Rochester, Rochester, MN, USA.
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Price
authors.affiliation: Department of Otorhinolaryngology, Mayo Clinic Rochester, Rochester, MN, USA.
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Moore
authors.affiliation: Department of Otorhinolaryngology, Mayo Clinic Rochester, Rochester, MN, USA.
authors.forename: Kerry D
authors.initials: KD
authors.lastname: Olsen
authors.affiliation: Department of Otorhinolaryngology, Mayo Clinic Rochester, Rochester, MN, USA.
authors.forename: Jan L
authors.initials: JL
authors.lastname: Kasperbauer
authors.affiliation: Department of Radiation Oncology, Mayo Clinic Rochester, Rochester, MN, USA.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Foote
authors.affiliation: Division of Medical Oncology, Department of Oncology, Mayo Clinic Rochester, Rochester, MN, USA. Electronic address: price.katharine@mayo.edu.
authors.forename: Katharine A
authors.initials: KA
authors.lastname: Price
authors.affiliation: Division of Anatomic Pathology, Department of Laboratory Medicine & Pathology, Mayo Clinic Rochester, Rochester, MN, USA.
authors.forename: Joaquín J
authors.initials: JJ
authors.lastname: García
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018267:Carcinoma, Acinar Cell / Q000235:genetics / Q000473:pathology* / Q000601:surgery; D005260:Female; D015321:Gene Rearrangement; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011379:Prognosis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012468:Salivary Gland Neoplasms / Q000235:genetics / Q000473:pathology* / Q000601:surgery; D015996:Survival Rate