Metastatic xanthogranulomatous pyelonephritis managed with immunosuppression

A male aged in his mid-60s was diagnosed with xanthogranulomatous pyelonephritis after a left nephrectomy for a renal mass that was detected during the investigation of weight loss and drenching night sweats. Past medical history includes type 2 diabetes mellitus, transient ischaemic attack, hypertension, non-alcoholic fatty liver disease, dyslipidaemia, osteoarthritis and active smoking. Three years after the initial diagnosis, the patient represented with abdominal pain. CT imaging demonstrated new pulmonary and pancreatic lesions, which were histologically confirmed to be xanthogranulomatous disease. The patient was too unstable for surgical intervention so was commenced on glucocorticoids with marked improvement in his clinical condition with resolution of inflammatory markers and radiographic improvement. Weaning of prednisolone led to a relapse of disease, which was managed with re-introduction of high-dose prednisolone and the initiation of azathioprine. The patient is now 2 years post initiation of immunosuppressive therapy with stable renal function and no active inflammation.