Varying appearance of focal nodular hyperplasia in nuclear medicine imaging.

The focal nodular hyperplasia (FNH) is the second most common benign hepatic tumor, which contains variable quantities of normal hepatic cellular elements: Kupffer cells, hepatocytes, bile ducts, and blood vessels. Two patients with suspicion of FNH were investigated by colloidal, blood pool, and hepatobiliary scintigraphy. Dynamic perfusion examination (with labeled RBCs), planar and SPECT studies were performed in all cases. Diagnosis was confirmed by histologic examination. We suggest the importance of combined imaging because of various appearance of the tumor. In our experience SPECT imaging after a planar study is a useful sequence, especially in small tumors in the exact location of activity.