Department of Urology, Teikyo University School of Medicine, 2-11-1 Kaga, Itabashi, Tokyo 173-8606, Japan.
Adrenal myelolipomas are uncommon, nonfunctioning tumors that tend to be discovered incidentally on imaging. Such tumors are composed of mature adipose tissue and hematopoietic elements, but their etiology is still unknown. Thyroid hormones have important effects on development, growth, and metabolism, as well as tumorigenesis. We report a case of adrenal myelolipoma in a patient with hyperthyroidism; this benign tumor expressed both thyroid hormone receptor alpha and beta.