The Importance of Recognizing Hibernomas as Possibly Not So Rare Pitfalls in FDG PET—A Histologically Verified Case and Literature Review

We present a glucose avid hibernoma hampering the re-staging of advanced breast cancer with FDG PET and summarize the results of the available literature. FDG PET, CT, MRI, ultrasound and histology were performed according to standardized protocols in our case. The literature search was performed on PubMed.gov. The literature search revealed 29 relevant publications starting with 2002. The high metabolic activity of hibernomas is a precarious pitfall in the staging of patients with a high pretest probability of malignancy and an increasing number of published cases indicate a possibly underestimated problem necessitating histological work-up in most cases. In our experience and in accordance with the literature unusually high uptake of a lesion and fat equivalent density in the CT should raise the suspicion for a hibernoma. The differential diagnosis between hibernomas and liposarcoma is often impossible without biopsy and histological work-up to prevent unnecessary treatment.