MRCP2-4066

MRCP2-4066

A 33-year-old man with a history of sickle cell anemia presents with left-sided loin pain and hematuria for the past three days. The pain is localized and does not radiate to the groin. He has been in good health for several years since his last crisis. He reports recent knee pain related to exercise, which he has been managing with ibuprofen.

During the examination, the patient is tender in the left loin, and a urine sample shows red coloration with visible pieces. There is no jaundice or scleral icterus, but a palpable spleen is felt 2 cm below the costal margin. Further investigations are carried out.

Sodium: 136 mmol/l
Potassium: 4.6 mmol/l
Urea: 5.2 mmol/l
Creatinine: 89µmol/l

Hemoglobin: 96 g/l
Platelets: 178 * 109/l
White blood cells: 9.7* 109/l

Ultrasound of the renal tract reveals a clubbed appearance of calyces and debris in the renal pelvis.

What is the most likely diagnosis?