Congenital absence of the portal vein in a boy.

Congenital absence of the portal vein (CAPV) is a malformation that is generally thought to be limited to females. We encountered an 11-year-old boy with this malformation. In 17 previously reported cases of CAPV, 2 were male. Three male patients, including our case, were Abernethy type Ib malformation. They had no associated liver tumour and two had no additional congenital abnormality. Conversely, 13 of the 15 female patients had congenital abnormalities and 6 had liver mass lesions.