Case presentation. A 68-year-old man with a history of advanced cirrhosis was referred to our institution by his primary care doctor for evaluation of possible liver transplantation due to advanced cirrhosis. Physical examination revealed classical findings for alcoholicinduced cirrhosis including bilateral non-tender gynecomastia.
As part of the patient's comprehensive preoperative evaluation, he underwent a pharmacologic (adenosine) nuclear stress test with Myoview (technetium 99m tetrofosmin) (GE Healthcare, Buckinghamshire, England): 11.9 mCi was injected at rest and 31.9 mCi during the adenosine phase of the stress test.
There was no evidence of resting or stress perfusion defects. Raw cine images revealed uptake of the tracer in the mammary tissue (Figure 1).
Discussion. The patient's medical regimen included spironolactone, an aldosterone receptor antagonist, which is typically used in the treatment of cirrhotic edema thought to be associated with excessive aldosterone secretion. 1 Endocrine system effects of spironolactone include gynecomastia, hirsutism, menstrual abnormalities, and decreased libido. Spironolactone has a strong affinity for progesterone and androgen receptors; it also produces an alteration of the testosterone-estrogen ratio in favor of estrogen. Spironolactone blocks androgen production by inhibiting 17โฃ-hydroxylase and 17,20desmolase, 2 major enzymes in the testosterone synthetic pathway. Other mechanisms by which spironolactone may enhance mammary tissue uptake include blocking testosterone and dihydrotestosterone from binding to their receptors, increasing serum-free estradiol by displacing estradiol from sex hormone-binding globulin, and augmenting peripheral conversion of testosterone to estradiol. 2