RET/PTC-1 and RET/PTC-3 were detected in 126 PTCs using reverse transcription-polymerase chain reaction (RT-PCR) and direct sequencing.     ///    High frequency of level II-V lymph node involvement in RET/PTC positive papillary thyroid carcinoma..     ///    The RET/PTC positive patients should receive more attention to lateral neck in the management of PTC..     ///    RET/PTC-1 positive patients were more likely to suffer from Hashimoto's thyroiditis simultaneously (P=0.02) while RET/PTC-3 positive patients had a higher frequency of extrathyroidal extension (P<0.01) and advanced T classification (P<0.01).     ///    RET/PTC-1 and RET/PTC-3 are associated with different clinical pathological characteristics but not with lymph node involvement. 