Are RET/PTC rearrangements in benign thyroid nodules of biological significance?

摘要

RET/PTC are chimeric oncogenes generated by the fusion of the catalytic domain of the tyrosine kinase receptor RET to the 5' terminal region of heterologous genes. While initially RET/PTC expression was considered restricted to papillary thyroid cancer (PTC), highly sensitive detection techniques disclosed the presence of this oncogene also in nonmalignant thyroidal diseases like Hashimoto's thyroiditis, adenomas, and benign colloid nodules (1). To date, the biological significance of RET/PTC in benign thyroid lesions controversial. While it could represent an event in the transition to malignancy, it might affect cell behavior in other ways. Here, we present a patient with a thyroid nodule that was benign on cytology and histopathology. Molecular analysis revealed that it harbored RET/PTC. Because of the juxtaposition of this with a distinctive clinical course, we speculated that RET rearrangements may be associated with more rapid nodular growth.