A Case of Primary Renal Carcinoid Tumor

Abstract EN

Primary renal carcinoid tumors are extremely rare kidney lesions, with fewer than 100 reported cases previously.

We describe a 75-year-old man with an incidentally detected cystic renal mass.

Computed tomography showed a 3 cm tumor with a cystic component enhanced with contrast.

No evidence of metastasis was detected.

We treated the patient with radical nephrectomy.

Pathological examinations revealed a cellular arrangement specific to carcinoid tumor and positive for chromogranin A, neural cell adhesion molecule, and somatostatin receptor type 2.

The tumor cells had a mitotic count of 4 mitoses/10 high-power fields, and the level of the proliferation marker Ki-67 was 5%.

The pathological diagnosis was renal neuroendocrine tumor grade 2.

No local recurrence and no systemic metastasis were detected during the 18-month follow-up period.

To our knowledge, this is the 6th case of renal neuroendocrine grade 2 tumor reported thus far.