Distant metastatic spread of molecularly proven infantile fibrosarcoma of the chest in a 2-month-old girl: case report and review of literature.

Infantile fibrosarcoma (IFS) is a malignant neoplasm, arising in children younger than 2 years of age and with a hallmark chromosomal translocation t(12;15)(p13;q26) encoding an ETV6-NTRK3 fusion oncoprotein. A review of the world literature found no reported cases of molecularly proven IFS with distant metastatic spread at presentation. We report the case of a 2-month-old infant girl presenting with a chest wall primary IFS bearing and expressing the ETV6-NTRK3 fusion, who had several pulmonary metastatic deposits at diagnosis. She achieved complete remission with chemotherapy and surgery. To our knowledge, this is the first reported case of molecularly proven IFS with distant metastatic spread.