ABSTRACT
Purpose To analyze the morphological charac-teristics of papillary thyroid carcinoma(PTC)patients with NTRK gene fusion in order to provide more important morpholog-ic evidences for molecular detection.Methods A retrospective collection of 790 cases PTC was conducted.Then the patients with NTRK gene fusion were selected.The histopathological fea-tures of PTC patients with NTRK gene fusion were compared with those of classical PTC.Results Nine cases(1.1%)of NTRK fusion positive PTC were detected,including 2 cases of NTRK1 and 7 cases of NTRK3 gene fusion.The main his-topathological features were follicular subtypes,with tumors ex-hibiting multinodular infiltration or"jumping"infiltration.The cytoplasm was associated with hyaline change.The cell morphol-ogy was slight irregularity.Conclusion The incidence of NTRK fusion is low in PTC and it tends to occur in the young group.Follicular subtype is the main characteristic histopatholo-gy,with mild tumor cells.But the ability of the invasion and metastasis is strong.Therefore,NGS detection should be per-formed for early intervention and prolonging the survival of PTC patients.