HEY1-NCOA2 Fusion Transcript Detection Is a Valuable Diagnostic Adjunct in the Diagnosis of Mesenchymal Chondrosarcoma
Angela Niblett, Gillian Bartle, Florian Puls. Royal Orthopaedic Hospital, Birmingham, West Midlands, United Kingdom
Background: Mesenchymal chondrosarcoma (MC) is a rare sarcoma of children and young adults arising in bone and soft tissues. Morphological diagnosis is often challenging since its salient biphasic morphology is often not represented on small biopsy material. Appearances also overlap with other entities. Novel Hey1-NCOA2 fusion transcripts were recently identified in MC suggestive that this is the defining genetic alteration which can be exploited for diagnostic use.
Design: RNA was extracted from 12 MC from 12 patients (7 biopsies, 5 resection specimens). RNA quality was assessed by beta-actin amplification (98 bp amplification product). HEY1-NCOA2 fusion transcript were detected by RT-PCR (119 bp amplification product) and confirmed by sequencing.
Results: Adequate RNA could be extracted from 9 out of 12 MC. HEY-NCOA2 fusion transcripts were detected in all 9 cases. Sequencing confirmed the exact in-frame HEY1 exon4–NCOA2 exon13 fusion as described in the initial cases. In two positive biopsies a tentative diagnosis of MC was given based on limited material highlighting the diagnostic benefit of transcript detection.
Conclusions: HEY1-NCOA2 fusion transcript is a consistent finding in MC. Detection by RT-PCR is a useful diagnostic adjunct especially in limited biopsy material. In contrast to other translocation sarcomas the fusion transcript is identical requiring only a single primer pair.
Category: Bone & Soft Tissue
Monday, March 4, 2013 1:00 PM
Poster Session II # 17, Monday Afternoon