1. ¹Department of Pathology, Haartman Institute and HUSLAB, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland
2. ²Department of Pathology, University of Virginia Health System, Charlottesville, VA, USA

Correspondence: Dr EB Stelow, MD, Department of Pathology, University of Virginia Health Sciences, Box 800214, Jefferson Park Avenue, Charlottesville, VA 22908, USA. E-mail: edstelow@yahoo.com; Dr S Knuutila, PhD, Department of Pathology, Haartman Institute and HUSLAB, PO Box 21 (Haartmaninkatu 3), University of Helsinki, FI-00014 Helsinki, Finland. E-mail: Sakari.Knuutila@helsinki.fi

Received 24 November 2007; Revised 2 March 2008; Accepted 10 March 2008; Published online 11 April 2008.

Abstract

Olfactory neuroblastoma is an unusual neuroectodermal malignancy, which is thought to arise at the olfactory membrane of the sinonasal tract. Due to its rarity, little is understood regarding its molecular and cytogenetic abnormalities. The aim of the current study is to identify specific DNA copy number changes in olfactory neuroblastoma. Thirteen dissected tissue samples were analyzed using array comparative genomic hybridization. Our results show that gene copy number profiles of olfactory neuroblastoma samples are complex. The most frequent changes included gains at 7q11.22–q21.11, 9p13.3, 13q, 20p/q, and Xp/q, and losses at 2q31.1, 2q33.3, 2q37.1, 6q16.3, 6q21.33, 6q22.1, 22q11.23, 22q12.1, and Xp/q. Gains were more frequent than losses, and high-stage tumors showed more alterations than low-stage olfactory neuroblastoma. Frequent changes in high-stage tumors were gains at 13q14.2–q14.3, 13q31.1, and 20q11.21–q11.23, and loss of Xp21.1 (in 66% of cases). Gains at 5q35, 13q, and 20q, and losses at 2q31.1, 2q33.3, and 6q16–q22, were present in 50% of cases. The identified regions of gene copy number change have been implicated in a variety of tumors, especially carcinomas. In addition, our results indicate that gains in 20q and 13q may be important in the progression of this cancer, and that these regions possibly harbor genes with functional relevance in olfactory neuroblastoma.