Hepatoadenoma and focal nodular hyperplasia: pitfalls in radiocolloid imaging.

Both hepatoadenoma and focal nodular hyperplasia must be considered in the differential diagnosis of right upper quadrant pain or mass in young women taking oral contraceptives. Three new cases are presented, and the radionuclide scan findings of 35 additional cases reviewed. There is great variability in the radiocolloid liver scans of these entities. Hepatoadenomas often develop along the inferior margin of the liver, and may therefore go undetected by radiocolloid imaging.