Peripelvic Cyst on Renal POCUS 60s f admitted with acute pyelonephritis, CT scan reveals no hydronephrosis/stone/abscess, continues to worsen despite abx. HPI: 1 day of acute onset colicky left flank pain, nausea, vomiting --> chills/rigors, generalized weakness, lethargy. At baseline: independent, active T 101 in ED, BP 124/84, HR 80s +L CVA tenderness UA no blood, WBC, leukesterase, or nitrite. 1+ prot CT A/P w IV con: abnormal hypoattenuation of the left kidney with fat stranding while could relate to pyelonephritis. Correlate with UA. No hydroneprosis. No collecting system stone WBC 12.5 Cr 0.7 BUN 16 lactate 2.0. LFTs normal Diagnosed with acute pyelonephritis and given ceftriaxone. Despite this, she continues to worsen over the next 24 hours. Vitals: BP 80s/50s, HR 120s, T 101, SpO2 98% RA. worsening colicky flank pain, rigors. Lactate up to 4.0. BPs improve with 2L LR. Pt and family are concerned that something is being missed. You recall that pyelonephritis takes time to improve (often days) Here, POCUS of the left kidney was performed for a few reasons 1) For pt/family reassurance through a thorough bedside assessment 2) Sonopalpation - localization of tenderness to help confirm diagnosis 3) To assess for interval development of hydronephrosis POCUS interpretation: hypoechoic contents in superior pole of the left kidney, and left renal pelvis. Not classic for hydronephrosis. Also considered some kind of abscess or infected cyst. Overall: fluid collection in kidney of a pt w pyelo and worsening condition was concerning, though exact pathology was tough to name. Regardless of CT and POCUS, with clinical status of pt and with X-ray showing retained contrast in renal pelvis, pt was taken to OR. Ureteroscopy revealed obstruction at left renal pelvis --> stented w release of pus. Obstruction attributed to pressure from peripelvic cysts. Importantly, peripelvic cysts may be a cause of "false positive" for hydronephrosis (JUM 1982) Though usually asymptomatic, occasionally may cause obstruction and pyelonephritis - Pitt Internal Medicine Point of Care Ultrasound @PittIMPOCUS #Peripelvic #Cyst #Renal #POCUS #kidney #clinical #ultrasound
