RESUMEN
BACKGROUND: Recently, the ETV6-NTRK3 gene fusion has been identified in both infantile fibrosarcoma and cellular mesoblastic nephroma. For both these tumors standard curative treatment has been primarily surgical with wide local excision. This has frequently involved radical and even mutilating surgery. PROCEDURE: This report discusses three infants with congenital tumors, two congenital fibrosarcomas, and one atypical congenital mesoblastic nephroma, not easily amenable to surgical intervention. RESULTS: All three were treated with pre-operative chemotherapy with excellent responses negating the need for amputation in two patients. In each patient, the ETV6-NTRK3 gene fusion was identified by reverse transcriptase-polymerase chain reaction (RT-PCR) in the tumor specimens. CONCLUSIONS: Our findings suggest that the ETV6-NTRK3 gene fusion may underlie the distinctive biological properties of these tumors and may also indicate tumor chemosensitivity. In this group of patients pre-operative chemotherapy may abrogate the need for morbid surgical procedures.