Angiomyxoma of the umbilical cord with massive cystic degeneration of Wharton's jelly.

Tumors of the umbilical cord, and especially angiomyxomas, are extremely unusual placental lesions. Sonography three weeks after the finding of a slightly elevated amniotic fluid alpha-fetoprotein, detected a cystic lesion of the umbilical cord in a 35-year-old woman at 19.5 weeks gestation. Two prior sonograms had been normal (16.2 and 17.5 weeks gestational age). After delivery of a normal female infant at 38.5 weeks, a pathologic examination revealed an angiomyxoma of the umbilical cord with massive cystic degeneration of Wharton's jelly. The tumor was twice the size of cases cited previously and cystic degeneration was massive. Serial sonography afforded a unique opportunity to study the development of this lesion in utero.