Teratoma is a germ cell tumor composed of 2 or 3 germ cell layers, and it can occur in various parts of the human body. However, teratomas of the renal hilum are particularly rare, and those complicated by carcinoids are even more uncommon. Herein, we report the example of an asymptomatic 49-year-old woman in whom a tumor in the right renal hilum was unexpectedly discovered on imaging. Histological examination revealed a carcinoid tumor arising from a simple cyst composed of teratomatous tissue. Although the tumor was located in the renal hilum and touched the renal parenchyma, it appeared independent of the kidney and urinary tract. This report highlights the rare occurrence of teratomas with carcinoids and provides insights into their origins.
Keywords: carcinoid; kidney; neuroendocrine tumor; renal hilum; retroperitoneal tumor; teratoma.