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Inflammatory myofibroblastic tumor arising from soft tissues of extremities harboring a novel CLIP2‐ALK fusion
Author(s) -
Ding Ru,
Li Xiao,
Zhu XiaoMei,
Song QuoXing,
Fan QinHe,
Zhang ZhiHong,
Gong QiXing
Publication year - 2020
Publication title -
pathology international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.73
H-Index - 74
eISSN - 1440-1827
pISSN - 1320-5463
DOI - 10.1111/pin.12988
Subject(s) - pathology , cd34 , soft tissue , fusion gene , desmin , fluorescence in situ hybridization , stroma , infiltration (hvac) , in situ hybridization , immunohistochemistry , lesion , biology , medicine , gene expression , gene , chromosome , vimentin , stem cell , biochemistry , genetics , physics , thermodynamics
A 34‐year‐old Chinese woman found a lump in her left leg for more than 3 weeks without any discomfort. Grossly, the tumor was relatively well delineated with focal infiltration. Histopathologic evaluation showed a compact fascicular spindle cell proliferation with variable myxoid and collagenous stroma and scattered inflammatory infiltrate. Immunohistochemically, the tumor cells showed positive expression of ALKD5F3 and SMA and negative expression of CD34, desmin, and cytokeretin. Fluorescence in situ hybridization analysis of the ALK locus showed break‐apart signals in 20% of tumor cells, and DNA sequencing discovered a novel CLIP2‐ALK fusion gene. The lesion was diagnosed as an inflammatory myofibroblastic tumor (IMT). To the best of our knowledge, this is the first case with CLIP2‐ALK gene fusion in the somatic soft tissue IMTs.