NTRK3 and ductal breast carcinoma in situ: Additionally, fusions observed in other subtypes of salivary gland carcinoma, such as ETV6::NTRK3 and NCOA4::RET described in secretory carcinoma and intraductal carcinoma, respectively [18, 19], have been reported in SDC without any histologic evidence of these other tumor types [13, 17].