BACKGROUND: Acute renal infarction often presents with abdominal  pain,  nausea,  vomiting,  and  fever.With other more common illnesses presenting with the same symptoms,
it is often misdiagnosed leading to delayed treatment.We present a case of a young female diagnosed to have Membranous Glomerulopathy who presented with sudden onset  flank  pain  in  whom was initially treated as urinary tract infection.
CASE: A  19-year-old  female  diagnosed  with  membranous glomerulopathy presented at the Emergency Room (ER) with severe,  right  sided,  flank  pain  of  acute  onset,  associated with nausea and vomiting. No fever, dysuria, hematuria, or history of trauma. Her vital signs were within normal range. Abdominal  examination  revealed  a  distended  but  soft non-tender  abdomen  with  positive  shifting  dullness and fluid wave test. Right sided costovertebral angle tenderness was  elicited.Initial diagnostics showed leukocytosis with neutrophilic  predominance,  serum  creatinine  of  0.77mg/dL,  and  proteinuria  of  >600mg/dL.Abdominal  ultrasound showed  non-specific  findings,  thus  contrast-enhanced  computed  tomography  scan  (CT-Scan)  of  the  abdomen was  done which revealed areas of non-enhancement in the upper to middle portions of the right kidney which may relate to areas of ischemia and/or infarction, likely due to thrombosis involving the more distal portion of the right renal artery and massive ascites. Result was confirmed by computed tomography angiography (CTA) of the kidneys showing right renal artery thrombosis. Evaluations for other causes  of  renal  artery  thrombosis  aside  from  patient's concurrent  membranous  glomerulopathy  were  done  and were negative. Anti-coagulation therapy was initiated using low molecular weight heparin (LMWH) and was thereafter maintained on warfarin.
CONCLUSION: A  high  index  of  clinical  suspicion  is  needed to  diagnose  acute  renal  infarction  because  of  its  non-specific symptoms which can mimic other conditions. Early diagnosis and prompt initiation of anti-coagulation therapy is  important  to  avoid  irreversible  kidney  damage.  Acute renal infarction should be considered as a cause of acute onset flank pain in patients with risk factors and normal initial screening test.