Chemolysis of a Uric Acid Stone in a Horseshoe Kidney

Abstract

Chemolysis of kidney stone is not unheard of. However, to our knowledge, there is no previous report of chemolysis of a kidney stone in a horseshoe kidney. We report the first ever case of chemolysis of a stone in a horseshoe kidney. As part of his visible haematuria workup 4 years ago, a 66-year-old gentleman with a history of gout was found to have a horseshoe kidney. In early 2017, he was seen in the urology clinic with some non-specific abdominal pain without a recent history of visible haematuria, lower urinary tract symptoms, and urinary tract infections. His CT KUB (computed tomography of kidneys, ureters and bladder), revealed a 1.3cm stone in his horseshoe kidney [Figure 1 and 2]. At the same time, his CT KUB has also picked up some retroperitoneal lymphadenopathy in the abdomen and pelvis which were suspicious of lymphoma. His serum uric acid level was noted to be normal. Subsequently, he underwent a laparoscopic right iliac lymph node biopsy which confirmed nodal marginal zone non-Hodgkin's B-cell lymphoma. He was reviewed by the haematology team and they decided to adopt a watch and wait approach to his disease with quarterly CT CAP (computed tomography of chest, abdomen and pelvis) scans. During this period of time, he had several gout attacks and he was started on allopurinol i.e. 100mg once a day. He also considerably increased his daily fluid intake. 6 months after his initial CT KUB, he was found to be completely stone free on his CT scan [Figure 3 and 4].