Unusual Tc-99m Methylene Diphosphonate Uptake by Clinically Suspected Adrenal Metastases From Hepatocellular Carcinoma

In a 64-year-old female patient with hepatocellular carcinoma and increasing serum alpha-fetoprotein level, a newly developed mass lesion over the right adrenal region was detected by computed tomography, whereas the same lesion also demonstrated prominent fluorodeoxyglucose uptake on the following fluorodeoxyglucose positron emission tomography/computed tomography. Then, adrenal metastasis was clinically diagnosed. Interesting, a cap-like Tc-99m methylene diphosphonate uptake over the right suprarenal region of right kidney was noted on the whole body bone scan, which was not shown on the prior study in 1 year ago. In this case, bone-seeking agents unusually accumulated within the supra-renal lesion are highly associated with adrenal metastasis, which is rarely reported before, and the possible etiologies are being discussed.