原發性類癌瘤最常發生在腸道。根據文獻報告，原發性腎臓類癌瘤是非常少見的，之前大約只有四十名的案例報告。我們報告一位27歲的女性乳癌患者併發性腎臓類癌瘤的案伐。病患在電腦斷層追蹤時發現左腎有一腫瘤，一個月後，因左側腰痛再次接受檢查。發現左腎有被膜下血腫。再過二個月後的電腦斷層檢查顯現此血腫變大，而且左腰痛加劇並伴隨高血壓的發生。因此，在腎腫瘤合併出血的懷疑下，病患接受腎臓根除手術。病理報告顯示在腎皮質有一類癌瘤。根據我們所知，過去並沒有乳癌患者併有原發性腎臓類癌瘤的案例報告，同時，我們也對過雲的文獻做一回顧。

Primary carcinoid tumors are mostly found in the intestinal tract. In the literature, a primary renal carcinoid tumor is a very rare neoplasm and only about 40 cases have been reported. We herein describe a rare case of a primary renal carcinoid tumor with hemorrhage in a 27-year-old woman with breast cancer. She presented with abdominal pain, and a left renal mass with suspected hematoma was our initial impression. She received a radical nephrectomy for the hemorrhagic renal tumor because of an in creasing size of the mass and exacerbated pain. The pathological finding showed a tumor within the renal cortex, and immunohistochemical analyses of this tumor revealed features typical of a carcinoid tumor. To our knowledge, no case of primary renal carcinoid tumor presenting in a patient with breast cancer has been reported. This unusual case is discussed, and the literature is reviewed.