Right flank pain: what’s more than a stone and a bug?

Introduction: Renal infarction (RI) is considered as rare condition; however, the incidence is underestimated due to the under diagnosis. Prompt diagnosis is crucial to prevent permanent loss of renal function. Case Description: This case involved a 61-year-old African American female who presented with sudden onset of severe constant right flank pain and right upper quadrant abdominal pain. Her history was significant for uncontrolled Type 2 diabetes, untreated hypertension, long standing smoking and intermittent use of marijuana. Patient had a blood pressure of 187/88 mmHg with otherwise normal vital signs upon presentation. She had moderate tenderness to palpation of the right upper quadrant of the abdomen, and significant right costovertebral angle tenderness. Initial lab work was unremarkable and her urine was positive for nitrites and no bacteria. Computer tomography of the abdomen without contrast and renal ultrasound ruled out nephrolithiasis or any other acute pathology of abdomen or pelvis. Patient continued to have severe right flank pain despite frequent use of intravenous narcotics and antibiotics. She had an unexplained creatinine elevation overnight. Repeated lactic acid remained negative. Renal doppler ultrasound revealed total occlusion of the right renal artery. The right kidney was deemed to be non-salvageable as it was out of the window for reperfusion. Extensive workup, including lipid panel, hypercoagulability, and cardiac tests was only remarkable for HDL level of 17 mg/dL, and HbA1c of 7.6. The infarction was considered due to atherosclerosis and patient was started on anticoagulation treatment. Discussion: This case illustrates renal infarction as the rare cause of right flank pain with negative abdominal CT and renal ultrasound. Keeping the differential diagnosis in mind and knowing the proper radiological modality to perform, would help to recognize this condition promptly. Rapid diagnosis and institution of the appropriate therapy are essential for the prevention of permanent loss of renal function