DICER1 Mutation Detected in an Infant Guides Accurate Diagnosis of Auto-Amputated Embryonal Rhabdomyosarcoma

Background: The DICER1 mutation is a pathogenic, germline mutation that predisposes patients to uncommon malignancies at a young age. Case: A 6-month-old female infant presented with vaginal bleeding and a protruding vaginal mass of unclear pathogenesis. Chemotherapy was initially targeted toward a germ cell tumor; after pathologic testing and auto-amputation of the tumor, the patient was diagnosed with a rare DICER1-associated embryonal rhabdomyosarcoma. Subsequently, her treatment course was restructured and family genetic surveillance instituted. Summary and Conclusion: Consideration for DICER1 mutation in tumors with complex pathology and unique presentation is critical to aid in diagnosis and management, and direct future comprehensive surveillance.