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Analytical Cellular Pathology
Volume 33 (2010), Issue 5-6, Pages 217-228
http://dx.doi.org/10.3233/ACP-CLO-2010-0547

Genetic Profile of Adenoid Cystic Carcinomas (ACC) with High-Grade Transformation versus Solid Type

Ana Flávia Costa,1 Albina Altemani,1 Hedy Vékony,2 Elisabeth Bloemena,2 Florentino Fresno,3 Carlos Suárez,4 José Luis Llorente,4 and Mario Hermsen4

1Department of Pathology, University of Campinas/UNICAMP, Campinas, Brazil
2Department of Pathology, VU University Medical Center, Amsterdam, The Netherlands
3Department of Pathology, IUOPA, Hospital Universitario Central de Asturias, Oviedo, Spain
4Department of Otolaryngology, IUOPA, Hospital Universitario Central de Asturias, Oviedo, Spain

Copyright © 2010 Hindawi Publishing Corporation and the authors. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Background: ACC can occasionally undergo dedifferentiation also referred to as high-grade transformation (ACC-HGT). However, ACC-HGT can also undergo transformation to adenocarcinomas which are not poorly differentiated. ACC-HGT is generally considered to be an aggressive variant of ACC, even more than solid ACC. This study was aimed to describe the genetic changes of ACC-HGT in relation to clinico-pathological features and to compare results to solid ACC.

Methods: Genome-wide DNA copy number changes were analyzed by microarray CGH in ACC-HGT, 4 with transformation into moderately differentiated adenocarcinoma (MDA) and two into poorly differentiated carcinoma (PDC), 5 solid ACC. In addition, Ki-67 index and p53 immunopositivity was assessed.

Results: ACC-HGT carried fewer copy number changes compared to solid ACC. Two ACC-HGT cases harboured a breakpoint at 6q23, near the cMYB oncogene. The complexity of the genomic profile concurred with the clinical course of the patient. Among the ACC-HGT, p53 positivity significantly increased from the conventional to the transformed (both MDA and PDC) component.

Conclusion: ACC-HGT may not necessarily reflect a more advanced stage of tumor progression, but rather a transformation to another histological form in which the poorly differentiated forms (PDC) presents a genetic complexity similar to the solid ACC.