Renin-producing ovarian tumor. A case report with immunohistochemical and electron-microscopic study

A 39-year-old woman presented with arterial hypertension. Examination of the patient revealed elevated plasma renin activity, hyperaldosteronemia, hypokalemia, and a pelvic mass. Subsequently, an 11-cm right ovarian tumor mass with histologic features of an unusual stromal cell tumor was resected. Immunohistochemical studies demonstrated renin production by tumor cells. Organelles resembling mature renin granules were identified by electron microscopy. Although blood pressure normalized after the initial surgery, the hypertension resumed with later recurrence of the tumor. We believe the tumor originated from renin-secreting ovarian stromal cells, possibly granulosa cells.