Mammary-analog secretory carcinoma in children: Surgery or TRK inhibitors first?

We report two cases of pediatric mammary-analog secretory carcinoma (MASC), a male operated on at age 8 and a female operated on at 12, who are in remission 2 years after surgery. The diagnosis of MASC was challenging and established by identifying the ETV6::NTRK3 fusion transcript in both cases. Given the excellent results of TRK inhibitor treatments in adult MASC and pediatric tumors expressing an ETV6::NTRK3 fusion, they should probably be prescribed as first-line treatment in cases requiring surgery with foreseeable serious sequelae or metastatic disease.