Xanthogranulomatous pyelonephritis: Rare presentation of a rare disease
A 45-year-old female was referred to the radiology department for investigation of gradually progressive abdominal lump in right lumbar region which she first noticed about 6 months back. She had complains of right flank pain, fullness and pus in urine for the same duration, but intensity of pain has increased since last 15 days and had an episode of hematuria few days back. She also gave history of off and on fever, for which she took medications from local practitioners. However, she had no previous history of diabetes, hypertension, renal disease or urinary tract infection.\nOn local examination, temperature was slightly raised with an ill-defined firm to hard mass palpable in right lumbar region and was tender on palpation. Laboratory investigation showed leukocytosis with increase in neutrophil count. On admission, investigations done at our hospital showed raised blood serum creatinine (1.8 mg%) and urea (60 IU) level. However, blood sugar level was normal.\nAn X-ray kidney urinary bladder (KUB) showed a large soft tissue density mass in right lumbar region displacing bowel loops to the left side. Loss of right psoas shadow, blurring of pre-peritoneal fat planes and mild scoliosis of spine with concavity to right side was also noted []. CT abdomen was advised immediately which showed ill defined, poorly excreting right kidney with loss of corticomedullary differentiation. There was extensive heterogeneously enhancing collection with involvement of adjacent soft tissue in perinephric and pararenal space, pelvis and under surface of liver with involvement of ipsilateral psoas, quadratus lumborum and lateral abdominal wall muscles. No evidence of calculus was seen on CT. Inferior vena cava IVC was displaced anteriorly due to retroperitoneal lymphadenopathy; however, no evidence of extension of the lesion into IVC was seen []. A radiological diagnosis of Xanthogranulomatous pyelonephritis was suggested even in the presence of negative history of diabetes, prior episode of urinary infections, absence of calculus and presence of hematuria.\nDrainage of extrarenal abscess under coverage of piperacillin-tazobactum and metronidazole was performed and aspirate sent for cytology which showed lipid laden macrophages with few haemosiderin laden macrophages consistent with the diagnosis of Xanthogranulomatous type of Pyelonephritis []. This was followed by radical nephrectomy. The patient recovered well with uneventful post-operative period and patient was discharged on 7th post-operative day. The patient was last seen at 3 months follow up and has progressed well.