NYU Medicine Grand Rounds Clinical Vignette Han Na Kim PGY-2 January 26, 2011 U NITED S TATES D EPARTMENT OF V ETERANS A FFAIRS

The patient is a 24-year-old man with a past medical history of cystinuria, presenting to renal stone clinic for routine follow up. Chief Complaint U NITED S TATES D EPARTMENT OF V ETERANS A FFAIRS

The patient’s medical history began at age 11 when he was diagnosed with cystinuria after an incidental finding of a large staghorn calculus. The stone was removed percutaneously but the kidney had minimal recovery of glomerular filtration. History of Present Illness U NITED S TATES D EPARTMENT OF V ETERANS A FFAIRS

Since that time, he has had multiple episodes of acute on chronic renal failure secondary to nephrolithiasis in the contralateral kidney. Because the patient’s cystinuria was refractory to medical treatment, a left ileal ureter was created with a segment of bowel replacing the proximal 2/3 of the left ureter six years prior to admission. History of Present Illness U NITED S TATES D EPARTMENT OF V ETERANS A FFAIRS

The patient has since been doing well, until six months prior to presentation, when he stopped taking his medications, including tiopronin (a thiol) and potassium citrate, used for urinary alkalinization. He now presents to renal stone clinic for routine follow up. History of Present Illness U NITED S TATES D EPARTMENT OF V ETERANS A FFAIRS

Additional History Past Medical History: Cystinuria diagnosed 1997 Hypertension diagnosed 2000 Past Surgical History: Multiple percutaneous nephrolithotomies Left ureteral stent placement 2004 Creation of ileal ureter 2005 Social History: Denies tobacco or drug use and drinks alcohol occasionally. Works at a pharmaceutical company. U NITED S TATES D EPARTMENT OF V ETERANS A FFAIRS

Additional History Family History: Father: Renal Cell Carcinoma Obstructive Pulmonary Disease Sister: Cystinuria Allergies: No known drug allergies Medications (stopped taking six months prior to presentation): Lisinopril 10 mg daily Potassium Citrate 20 meq twice daily Tiopronin 2400 mg daily U NITED S TATES D EPARTMENT OF V ETERANS A FFAIRS

Physical Examination General: well appearing obese young male in no apparent distress Vital Signs: T: 98.6 F BP: 126/88 HR: 76 RR: 14 and O2 sat: 98% on room air Remainder of the physical exam was normal U NITED S TATES D EPARTMENT OF V ETERANS A FFAIRS

Laboratory Findings CBC: within normal limits Basic Metabolic panel: BUN: 30 Creatinine: 1.4 Remainder of the basic metabolic panel was within normal limits Hepatic panel: within normal limits U NITED S TATES D EPARTMENT OF V ETERANS A FFAIRS

Laboratory Findings Urinalysis: pH: 7.3 (4.5-8) Specific Gravity ( ) Negative protein Negative nitrate Small blood Small leukocyte esterase Microscopic analysis: Red blood cell count: 3-4 White blood cell count: 5-6 U NITED S TATES D EPARTMENT OF V ETERANS A FFAIRS

Concern for cystine stone reformation in the setting of medication non-adherence in a patient with cystinuria. Working Diagnosis U NITED S TATES D EPARTMENT OF V ETERANS A FFAIRS

CAT Scan Abdomen and Pelvis U NITED S TATES D EPARTMENT OF V ETERANS A FFAIRS

CAT Scan Abdomen and Pelvis U NITED S TATES D EPARTMENT OF V ETERANS A FFAIRS

Ileal Ureter U NITED S TATES D EPARTMENT OF V ETERANS A FFAIRS

Renal Ultrasound Atrophic right kidney with multiple echogenic stones throughout the parenchyma mostly in lower pole. No solid mass lesions Left kidney with component of compensatory hypertrophy. Three stones noted with largest one in the lower pole measuring 7.2 mm U NITED S TATES D EPARTMENT OF V ETERANS A FFAIRS

Cystine stone formation secondary to nonadherence with medications in this patient with known diagnosis of cystinuria. Working Diagnosis U NITED S TATES D EPARTMENT OF V ETERANS A FFAIRS

Patient was instructed to restart potassium citrate at a higher dose of 3 tablets twice daily and to maintain a high fluid intake and reduce dietary sodium and animal protein intake. Course U NITED S TATES D EPARTMENT OF V ETERANS A FFAIRS

Cystinuria with cystine stone formation secondary to medication non-adherence. Final Diagnosis U NITED S TATES D EPARTMENT OF V ETERANS A FFAIRS