TY - JOUR
T1 - Vocal cord inflammatory myofibroblastic tumor with mucoid deposits harboring TIMP3–ALK fusion
T2 - A potential diagnostic pitfall
AU - Yorita, Kenji
AU - Togashi, Yuki
AU - Nakagawa, Hideyuki
AU - Miyazaki, Katsushi
AU - Sakata, Seiji
AU - Baba, Satoko
AU - Takeuchi, Kengo
AU - Hayashi, Yoshihiro
AU - Murakami, Ichiro
AU - Kuroda, Naoto
AU - Oda, Yoshinao
AU - Kohashi, Kenichi
AU - Yamada, Yuichi
AU - Kiyozawa, Daisuke
AU - Michal, Michael
AU - Michal, Michal
N1 - Publisher Copyright:
© 2019 Japanese Society of Pathology and John Wiley & Sons Australia, Ltd
PY - 2019
Y1 - 2019
N2 - A 35-year-old Japanese man who had experienced hoarseness for 10 years presented with a vocal cord lesion. A gross examination revealed a left vocal cord polyp occupying two-thirds of the vocal space. The endoscopically resected lesion contained scattered atypical fibroblastic, stellate, or ganglion-like cells with mucoid stroma. Vacuolated cells were also seen. Lymphoplasmacytic infiltrate was largely undetectable. A vocal cord polyp was first suspected, but well-differentiated liposarcoma and inflammatory myofibroblastic tumor (IMT) were included in the differential diagnoses. The tumor cells were positive for anaplastic lymphoma kinase (ALK), calponin, and vimentin, and negative for other smooth muscle markers by immunohistochemistry. Structures resembling myofibroblasts were not observed by electron microscopy, which confirmed abundant rough endoplasmic reticulum in the tumor cells and accumulated lipid droplets in some tumor cells. ALK gene rearrangement was detected by fluorescence in situ hybridization, and TIMP3–ALK fusion was confirmed by 5′ rapid amplification of cDNA ends. We diagnosed the lesion as an IMT, and an ALK-rearranged stellate cell tumor may be postulated. This is the first report of a fusion partner gene of ALK in a case of laryngeal IMT.
AB - A 35-year-old Japanese man who had experienced hoarseness for 10 years presented with a vocal cord lesion. A gross examination revealed a left vocal cord polyp occupying two-thirds of the vocal space. The endoscopically resected lesion contained scattered atypical fibroblastic, stellate, or ganglion-like cells with mucoid stroma. Vacuolated cells were also seen. Lymphoplasmacytic infiltrate was largely undetectable. A vocal cord polyp was first suspected, but well-differentiated liposarcoma and inflammatory myofibroblastic tumor (IMT) were included in the differential diagnoses. The tumor cells were positive for anaplastic lymphoma kinase (ALK), calponin, and vimentin, and negative for other smooth muscle markers by immunohistochemistry. Structures resembling myofibroblasts were not observed by electron microscopy, which confirmed abundant rough endoplasmic reticulum in the tumor cells and accumulated lipid droplets in some tumor cells. ALK gene rearrangement was detected by fluorescence in situ hybridization, and TIMP3–ALK fusion was confirmed by 5′ rapid amplification of cDNA ends. We diagnosed the lesion as an IMT, and an ALK-rearranged stellate cell tumor may be postulated. This is the first report of a fusion partner gene of ALK in a case of laryngeal IMT.
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U2 - 10.1111/pin.12796
DO - 10.1111/pin.12796
M3 - Article
C2 - 31215130
AN - SCOPUS:85067432745
VL - 69
SP - 366
EP - 371
JO - Acta Pathologica Japonica
JF - Acta Pathologica Japonica
SN - 1320-5463
IS - 6
ER -