Medullary Sponge Kidney

A case of medullary sponge kidney is presented, as little has been published in the British literature on this subject, apart from a paper by Rubin, Cosbie Ross and Turner (1959), and a case described by Pyrah and Hodgkinson (1960) in a discussion of nephrocalcinosis; the condition is also known as cystic disease of the renal pyramids. Although previously considered rare, 14 cases found in 2,465 consecutive urograms (0·5 per cent) are described as part of a larger series by Palubinskas (1961). Formerly cases may well have been misinterpreted as tubular stasis, nephrocalcinosis, or renal tuberculosis, leading to an underestimation of the true incidence of the disease. The lesion is regarded as a congenital anomaly, causing dilatation of the collecting tubules in the renal pyramids. Histopathological studies were made on material from 15 surgically treated cases by Ekström, Engfeldt, Lagergren and Lindvall (1959). The cysts were confined to the renal pyramids, and were lined with various types of epithelium, e.g. transitional, stratified squamous or columnar. Many cysts contained calculi, and in some of these epithelium was absent. A round cell inflammatory infiltration was a constant feature. The extent of the disease varied from involvement of a single pyramid in one kidney, to involvement of all the pyramids of both kidneys, but in the majority of cases both kidneys were affected to some extent.