ALK-negative inflammatory myofibroblastic tumor of lung with ETV6-NTRK3 fusion:a case report
LIU Ye-xin
ZHONG Bi-ling
WANG Gui-ming
LI Dan-qing
LI Yi-ming
Abstract：Some histologically typical inflammatory myofibroblastic tumors (IMTs) are ALK-negative. Inflammatory myofibroblastic tumors with ALK negativity and ETV6-NTRK3 fusion are rarely reported in China. This article reports a case of pulmonary inflammatory myofibroblastic tumor occurring in a 15-year-old female adolescent. Microscopically, the tumor cells showed a dense arrangement of spindle-shaped fibroblast-like cells, arranged in bundles or interwoven patterns, with significant infiltration of lymphocytes and plasma cells in the stroma. Immunohistochemical staining showed that the tumor cells were pan-TRK positive, with positivity localized in both the nucleus and cytoplasm. ALK (5A4, D5F3) was negative. RNA sequencing (RNA-seq) detected ETV6-NTRK3 gene fusion, and fluorescence in situ hybridization (FISH) confirmed ETV6 gene breakage positivity. When clinical data and histological morphology suggest IMT but ALK immunohistochemistry is negative, in addition to performing pan-TRK and ROS1 immunohistochemistry for assistance in diagnosis, FISH testing for non-ALK gene fusions and/or next-generation sequencing methods can be used to further confirm the diagnosis.
Keywords：Inflammatory myofibroblastic tumorLungALKETV6NTRK3ROS1
Publication Date：2025-06-28
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：4( 732-735 )