Primary adrenal mature cystic teratoma: A rare retroperitoneal tumor with two decades of indolent growth.

A 37-year-old woman presented with a 17-year history of intermittent right flank and epigastric discomfort that had recently worsened, together with bloating and early satiety. Contrast-enhanced computed tomography demonstrated a large right suprarenal mass containing fat and calcified components, unchanged in character but markedly enlarged compared with imaging obtained 17 years earlier. Open total adrenalectomy was performed without complications. Histopathology confirmed a mature cystic teratoma without malignant elements. This case illustrates an unusually indolent natural history of primary adrenal mature cystic teratoma and underscores its inclusion in the differential diagnosis of chronic suprarenal masses.