Autosomal Dominant Polycystic Kidney Disease, incidental finding with trauma: Case report and review of the literature

Introduction: Pre-existing renal lesions predispose kidneys to effects of otherwise insignificant blunt trauma, and may uncommonly present as an incidental finding in the workup of a suspected renal injury.Observation: This is a case report of a 28-year-old male diagnosed incidentally with Autosomal Dominant Polycystic Kidney Disease (ADPKD) as part of the workup for suspected kidney injury secondary to assault by a brick. This case study serves as a learning opportunity and future reference in the cases and management of blunt trauma to kidneys with pre-existing lesions and also to raise the index of suspicion for renal abnormalities in future cases of mild blunt abdominal trauma that present with significant injury to the kidney. The study design takes the form of a case report and an overview of the relevant literature by searching the following databases: Pubmed, Google Scholar, Cochrane library and Medline. Search terms included: “Abnormal Kidneys”, “Pathologic Kidneys”, “Polycystic Kidneys”, “Autosomal Dominant Polycystic Kidney Disease”, “Trauma”, “Blunt Trauma”, “Blunt Abdominal trauma”, “Blunt Renal Trauma”, “Pre-Existing Renal Lesions”. The literature search revealed 42 published cases of trauma to pre-existing renal lesions. 8 out of the 42 cases involved trauma to patients with Autosomal Dominant Polycystic Kidney Disease (ADPKD) (19%). Among the 8 cases of ADPKD, 4 cases presented with gross haematuria. Abdominal CT was the diagnostic imaging of choice in all cases and revealed injuries ranging from cyst rupture to AAST Grade IV injury to the kidney. Four out of the 8 cases required nephrectomy, and 3 cases were managed conservative-/non-operatively.Conclusion: Patients with abnormal kidneys require counselling regarding increased risk of injury following blunt abdominal trauma.The decision to transfuse a patient following renal trauma to pre-existing renal lesion possibly requiring a renal transplant, should be done with consideration of the increased risk of antigen sensitization. Patients that present with signs and symptoms out of proportion with the mechanism of trauma should raise the suspicion of undiagnosed pre-existing renal lesions.In cases of blunt renal trauma with a history suggesting the possibility of a pre-existing lesion, the threshold for requesting CT of the abdomen should be lowered, even in absence of gross haematuria.Keywords: Autosomal Dominant Polycystic Kidney Disease; Renal trauma; Pre-existing renal lesion; Blunt abdominal traum