The authors present the ninth case of primary carcinoid tumour arising in a
horseshoe kidney: The diagnosis and treatment were delayed dire to the ben
ign cystic appearance of the initial lesion. This exceptional association m
ust be kept in mind, as horseshoe kidney is associated with an increased ri
sk of malignant tumours, especially for carcinoid tumours. The minimally ag
gressive nature of these tumours generally allows limited surgical resectio
n.