[1164] CTRC1/ MAML2 Fusion Transcript in Central Mucoepidermoid Carcinoma of Mandible – Diagnostic and Histogenetic Implications.

Diana Bell, Christopher F Holsinger, Adel K El-Naggar. University of Mississippi Medical Center, Jackson; University of Texas M.D. Anderson Cancer Center, Houston

Background: Intraosseous salivary gland carcinomas are extremely rare, comprising only 2–3% of all mucoepidermoid carcinomas (MECs) reported. The t(11;19) translocation and its CRTC1/MAML1 fusion transcript have been identified in MEC at different sites and are believed to be associated with the development of a subset of these tumors. However, the status of the fusion transcript has not been reported in intraosseous MEC.
Design: Here, we report three examples of central MEC of the mandible, including a case with a history of primary retromolar MEC. Reverse transcriptase–polymerase chain reaction (RT-PCR) and DNA sequencing analyses of the microdissected components of these tumors were used for detection and verification of the fusion transcript.
Results: We identified, for the first time, the t(11;19) fusion gene transcript in central MEC, including in the previous primary retromolar MEC. No fusion transcript was detected in the second primary non-central MEC or in another central MEC. The results indicate that central MEC can manifest the fusion transcript.
Conclusions: Our findings show that central MEC of the mandible can manifest the fusion transcript. In case 3, the lack of the fusion transcript in the primary non-central MEC indicates an independent central second primary tumor. Since the initial clinical and radiological diagnosis in two central low-grade MECs was a benign odontogenic cyst, our findings support a future role for the fusion analysis in initial diagnostic efforts. In summary, we have identified, to our knowledge for the first time, t(11;19) fusion gene transcripts in a subset of central MEC, originating from ectopic salivary rests, and the absence of the fusion transcript in MEC with glandular odontogenic precursors. This finding may have diagnostic and histogenetic roles in the future analysis of this entity.
Category: Head & Neck

Wednesday, March 2, 2011 9:30 AM

Poster Session V # 146, Wednesday Morning

 

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