Rapid growth of a kidney angiomyolipoma after initiation of oral contraceptive therapy

BACKGROUND: Kidney angiomyolipomas are benign but progressive tumors consisting of smooth muscle, fat, and vascular elements, commonly associated with the tuberous sclerosis complex. Angiomyolipomas express estrogen and progesterone receptors and have been reported to increase in size in pregnancy. CASE: A 15-year-old girl with stable angiomyolipomas of tuberous sclerosis complex was treated for menorrhagia with estrogen/progestin oral contraceptive pills. During the 12 months of contraceptive therapy, a new 4-cm exophytic angiomyolipoma developed that required selective arterial embolization to reduce its risk of spontaneous rupture. CONCLUSION: Treating menorrhagia with exogenous hormonal therapy in women with tuberous sclerosis complex should be accompanied by regular renal imaging to reduce the risk of an unanticipated angiomyolipoma-related adverse event. Alternate nonhormonal therapies for menorrhagia may also be considered.