OLFACTORY NEUROBLASTOMA - DETECTION OF GENOMIC IMBALANCES BY COMPARATIVE GENOMIC HYBRIDIZATION

Olfactory neuroblastoma (esthesioneuroblastoma) is a very rare tumour of the olfactory mucosa. Morphological features and cytogenetic studie s strongly suggest a neuro-ectodermal origin. Up to now, cytogenetic s tudies are inconsistent. Some of them have proposed that the tumour be longs to the pPNET family. In the present study we describe genomic im balances in olfactory neuroblastoma in a 46-year-old woman by using th e molecular cytogenetic technique - comparative genomic hybridization (CGH) - in order to define the spectrum of genetic abnormalities in th e tumour. The anatomical location and morphological findings were the basis for the diagnosis of esthesioneuroblastoma. Immunohistochemical reactions for NSE, synaptophysin, chromogranin A, HNK-1/Leu-7 and S-10 0 revealed a characteristic immunophenotype. The CGH analysis showed m ultiple changes including DNA overrepresentations of chromosomes 4, 8, 11 and 14, partial DNA gains of the long arms of chromosomes 1 and 17 , deletions of the entire chromosomes 16, 18, 19 and X, and partial lo sses of chromosomes 5q and 17p. This study represents an early utilisa tion of the CGH technique in olfactory neuroblastoma and demonstrates that the tumour carries complex chromosomal aberrations.