NTRK -rearranged Spindle Cell Neoplasm of the Uterus: An Emerging Entity.

NTRK -rearranged spindle cell neoplasm is a recently described mesenchymal neoplasm that usually occurs in the uterine cervix of premenopausal women with variable clinical behavior. Typical immunohistochemical profile includes CD34 and S100 positivity with negative staining for desmin, estrogen receptor (ER), and progesterone receptor (PR). We report a case of NTRK -rearranged spindle cell neoplasm with a previously unreported fusion partner ( NTRK1::TIMP3 ) located within the uterine corpus and with an unusual staining pattern, diffusely positive for desmin and PR, while negative for CD34 and S100. We also provide a literature review of NTRK- rearranged spindle cell neoplasms of the uterine corpus.