Is renal medullary carcinoma the seventh nephropathy in sickle cell disease? A multi-center Nigerian survey.

INTRODUCTION

Previous studies had enlisted renal medullary carcinoma (RMC) as the seventh nephropathy in sickle cell disease (SCD). Clinical experience has contradicted this claim and this study is targeted at refuting or supporting this assumption.

OBJECTIVE

To estimate the prevalence of RMC and describe other renal complications in SCD.

MATERIALS AND

METHODS

14 physicians (haematologists and urologists) in 11 tertiary institutions across the country were collated from patients' case notes and hospital SCD registers.

RESULTS

Of the 3,596 registered sickle patients, 2 (0.056%) had been diagnosed with RMC over a ten year period, thereby giving an estimated prevalence rate of 5.6 per 100,000. The most common renal complication reported by the attending physicians was chronic kidney disease (CKD). The frequency of routine renal screening for SCD patients varied widely between centres - most were done at diagnosis, annually or bi-annually.

CONCLUSION

The ten year prevalence of RMC in Nigerian SCD patients was determined to be 5.6 (estimated incidence of 0.56). RMC is not more common in SCD patients and therefore cannot be regarded as a "Seventh Sickle nephropathy". Most of the managing physicians reported that the commonest nephropathy observed in their SCD patients was chronic kidney disease.