Atypical carcinoid presenting as dumb-bell-shaped tumour in the normal kidney.

Carcinoid tumours are low-grade malignant neoplasms with neuroendocrine differentiation and occur frequently in the gastrointestinal and respiratory tracts. Primary carcinoid tumours of the kidney are rare and a majority of these tumours occur in anomalous kidney and exhibit typical renal carcinoid morphology. We reported a middle-aged man with primary atypical carcinoid tumour occurring in a normal kidney. The patient was diagnosed as having renal cell carcinoma owing to a lack of neuroendocrinal clinical features. Immunohistochemical staining of the nephrectomy specimen helped in the diagnosis of atypical renal carcinoid.