Aldosterone secreting adrenal adenomas are responsible for about 70% of cases of primary aldosteronism (Conn Syndrome). The remainder of the cases are caused by cortical hyperplasia. Adrenocortical carcinomas that secrete aldosterone are exceedingly rare. Primary aldosteronism is manifested by urinary loss of potassium (causing hypokalemia and muscle weakness), sodium retention, and hypertension. Patients are often treated with Spironolactone pre-operatively before undergoing removal of adenomas. In such cases, the tumor cells may show whorled, multilamellar membranous eosinophilic structures in their cytoplasm - called Spironolactone bodies. They arise from smooth endoplasmic reticulum and contain bound aldosterone. Image courtesy of: Evita Sadimin, MD, Department of Pathology & Laboratory Medicine, Robert Wood Johnson Medical School, New Jersey, USA.