To the Editor.—Careful examination of the liver is a fundamental part of an exploratory laparotomy. Hepatic pathology is predictable by abnormal preoperative laboratory, roentgenographic, or isotopic studies. Recently, during an exploratory laparotomy for duodenal obstruction, we were unexpectedly confronted with an unusual liver lesion, not immediately recognizable. The liver was "peppered" with small, tan-green, subcapsular nodules, resembling metastases that frozen section showed to be bile duct adenomatosis.
This rare, benign entity appears microscopically as multiple multilocular cystic masses lined by cuboidal cells. These clusters of dilated ducts are contained in fibrous stroma and are benign-appearing. Except for mild distortion by these adenomas, the remaining liver parenchyma appears normal.1 Most feel bile duct adenomatosis is developmental, rather than inflammatory, obstructive, or neoplastic in cause. It has been proposed that the liver is derived from two anlage, one giving rise to the liver parenchyma and intralobular bile canaliculi and the