Background: Primary carcinoids are found mostly in the gastrointestinal tract. Primary carcinoid tumor of the kidney is rare; only 28 patients have been reported. Because of the rarity of the lesion, its radiological and clinicopathological features are not well characterized. At the same time, its prognosis and histogenesis is unknown.
Methods: A 62-year-old patient presented with a carcinoid tumor on the isthmus of the horseshoe kidney. Radiological, clinicopathological, and immunohistochemical tests were performed. The tumor was resected.
Results: Two years later, metastasis were observed in the liver. The metastasis were treated with percutaneous ethanol sclerotherapy (PET).
Conclusions: To our knowledge, this is the first case of primary renal carcinoid tumor present on the isthmus of the horseshoe kidney and the first case of carcinoid liver metastasis to be treated with PET.