Gas-forming infection in a renal cyst of a patient with autosomal dominant polycystic kidney disease

Sir, Autosomal dominant polycystic kidney disease (ADPKD) often leads to progressive renal failure due to enlargement of the cysts. Other renal manifestations that can occur include hypertension, urinary tract infection, haematuria, nephrolithiasis, and acute or chronic flank and abdominal pain. Renal cell carcinoma is an infrequent complication of ADPKD [1]. Approximately 30–50% of patients with ADPKD will have one or more renal infection during their lifetime. The primary clinical manifestations of renal infection in polycystic kidney disease are fever and flank pain, which may be associated with bacteraemia [2]. These infections may be due either to parenchymal infection or to an infected cyst. Distinguishing between these disorders is often difficult [3]. We present a case of adult polycystic kidney disease complicated by infection of the cysts with gas formation. A 40-year-old male patient was diagnosed with adult polycystic kidney disease with chronic renal failure on treatment with haemodialysis. The patient was admitted to the Nephrology department with fever and right flank pain. His laboratory findings were as follows: creatinine 11.5 mg/dl, urea 169 mg/dl, alanine aminotransferase (ALT) 17 U/l, aspartate aminotransferase (AST) 112 U/l, albumin 2.6 g/dl, lactate dehydrogenase (LDH) 481 U/l, leukocytes 9200, haemoglobin 7.2 g/dl, C-reactive protein (CRP) 187 mg/l. Abdomen radiograph showed an air level in the right upper abdominal quadrant (Figure 1). Abdominal ultrasonography confirmed the gas within the cyst in the right kidney. Abdominal computed tomography (CT) scan demonstrated the presence of gas within the cysts (Figure 2). Antibiotics were started (netranidazole, quinolone). Urgent nephrectomy was planned, but the patient died with sepsis. Plain abdominal x-ray showing gas shadow on the right, beneath diaphragm. Abdominal CT showing the gas within the cyst in the right kidney. Infection of cysts in adult polycystic kidney disease is rare. In a few cases, cyst infection with gas was reported. Zijl et al. reported an emphysematous cyst in the right native kidney which 7 months previously had been a haemorrhagic cyst in a kidney transplanted patient with ADPKD [4]. Lanzas et al. presented a haemodialysis patient with adult polycystic kidney disease who presented with sepsis secondary to infection of the renal cyst with gas formation [5]. These two cases were successfully treated with urgent nephrectomy. To our knowledge, this is the third case of cyst infection with gas formation in an ADPKD patient reported in the literature. Infection of cysts with gas formation in end-stage renal failure patients due to adult polycystic kidney disease is a very rare entity and urgent nephrectomy may save their lives. Conflict of interest statement. None declared. 1Nephrology2 Urology4 Internal Medicine Yuzuncu Yil University Van3 Nephrology Sutcu Imam University Kahramanmaras Turkey