Collecting duct carcinoma of the kidney

Abstract

Collecting duct carcinoma, also known as Bellini duct carcinoma is a rare renal tumour of high malignancy. Though generally symptomatic, the aggressive nature of most of these tumours is such that more than 50% of patients have metastatic disease at the time of initial diagnosis. We describe the case of a 59-year-old man who presented to our hospital with a periodical pain in the left lumbar region. Grey-scale sonography of the left kidney showed an ill-defined tumour, almost isoechoic to renal cortex. The tumour was centrally located, with extension to the cortex and did not cause bulging of the renal outline. On contrastenhanced ultrasonography (U/S) and on contrastenhanced magnetic resonance imaging (MRI), the tumour was inhomogeneously hypoenhancing. The patient underwent a left radical nephrectomy. Histological diagnosis indicated collecting duct carcinoma of the kidney. The differential diagnosis between conventional or papillary renal carcinoma may be difficult and in these cases the molecular genetic findings are important, since all tumours have shown monosomies for chromosomes 1,6,14,15 and 22 and have lacked the changes seen in either conventional or papillary renal carcinoma. The prognosis is poor and about two thirds of patients die of their disease within two years of diagnosis.