Hypertension resulting from a renin-secreting tumor was first reported in 1967 by Robertson et al. Kihara and coworkers subsequently coined the term juxtaglomerular cell tumor for a similar tumor in a young woman with hyperreninemic hypertension. Since the description of these first two cases, it has become clear that renin-secreting tumors of both renal and nonrenal origin can cause surgically curable hypertension. Primary reninism has been suggested as a more appropriate term for the clinical syndrome associated with renin-secreting tumors, both renal and extrarenal, whether benign or malignant.