Unusually elevated liver radioactivity on F-18 FDG PET in Hodgkin's disease - Hepatic 'superscan'

Increased focal concentration of FDG in the background of relatively lower normal hepatocyte uptake is usually regarded as the hallmark of metastatic involvement of the liver from a known primary. The authors present the clinical, radiologic, and laboratory profile of a very unusual hepatic uptake pattern in a case of Hodgkin disease, in which the FDG PET showed intensely diffuse hepatic tracer uptake and was the earliest indicator of extensive hepatic involvement by the disease process. The diagnosis of hepatic involvement with lymphoma was inferred. As experience with FDG PET is growing, it is important to become familiar with the various physiological and pathologic FDG uptake patterns. The term "hepatic superscan", demonstrating intense diffuse hepatic tracer uptake coupled with surprisingly low brain and cardiac FDG uptake, owes its origin from its apparent similarity with the superscan seen in conventional skeletal scintigraphy and represents an entity hitherto undescribed.