False positive diagnosis of metastatic esophageal carcinoma on positron emission tomography: a case report of cholecystitis simulating a hepatic lesion.

Esophageal cancer has been increasing in incidence for the last several decades. The current staging evaluation includes computed tomography, endoscopic ultrasonography, and F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT), which influences the treatment options. PET/CT is limited in its ability to differentiate hypermetabolic metastatic disease from acute/chronic inflammatory conditions, and this must be considered during interpretation. This is the case report of a 77-year-old man with esophageal cancer whose PET/CT demonstrated increased F-18 FDG uptake in the right lobe of the liver. This was originally interpreted at an outside institution as suspicious for metastatic disease, which would have precluded potential surgical cure. Subsequent reinterpretation and additional imaging including magnetic resonance imaging suggested that the uptake in the liver was likely due to adjacent gallbladder inflammation. On the basis of this interpretation, an abdominal exploration, liver biopsy, cholecystectomy, and transhiatal esophagectomy were performed. Final pathology of the gallbladder revealed perforated cholecystitis and a pericholecystic abscess (related to a prior septic episode), which were responsible for the increased radiotracer uptake. This case is presented to illustrate the importance of considering benign etiologies that may mimic metastatic disease when interpreting PET/CT scans.