An enlarging cystic-solid cord abnormality was found at prenatal identification to be an angiomyxoma. Partial in utero decompression of the 16 x 12 x 5 cm cystic component allowed uncomplicated spontaneous vaginal delivery at 36 weeks' gestation. Doppler studies had shown variable systolic/diastolic ratios in the solid component of the angiomyxoma.