A 21-year-old man comes to the emergency department due to 1 day of left flank pain and gross hematuria. He reports passage of small blood clots in urine but has had no dysuria or similar symptoms in the past. The patient has no other medical problems and does not take any medications. He does not use tobacco, alcohol, or illicit drugs. His younger sister has sickle cell disease. His temperature is 36.7 C (98 F), blood pressure is 126/70 mm Hg, and pulse is 100/min. Abdominal and genitourinary examination is unremarkable. There is no costovertebral angle tenderness. Which of the following is the most likely cause of this patient's hematuria?

Question

A 21-year-old man comes to the emergency department due to 1 day of left flank pain and gross hematuria.  He reports passage of small blood clots in urine but has had no dysuria or similar symptoms in the past.  The patient has no other medical problems and does not take any medications.  He does not use tobacco, alcohol, or illicit drugs.  His younger sister has sickle cell disease.  His temperature is 36.7 C (98 F), blood pressure is 126/70 mm Hg, and pulse is 100/min.  Abdominal and genitourinary examination is unremarkable.  There is no costovertebral angle tenderness.  Which of the following is the most likely cause of this patient's hematuria?

Quizplus · Accepted Answer

Abrupt-onset gross hematuria in an otherwise healthy patient with a family history of sickle cell disease suggests renal papillary necrosis (RPN) due to underlying sickle cell trait. Conditions associated with RPN include: Gray-white or yellow necrosis of the distal two-thirds of the renal pyramids is seen macroscopically and corresponds microscopically to coagulation necrosis with preserved tubule outlines; cortical surface scars can develop subsequently as inflammatory foci are replaced by fibrous depressions. Symptoms are due to sloughed papillae (sometimes visible in urine as tissue flecks) and include dark or bloody urine and colicky flank pain (due to ureteral obstruction). (Choices B and J) Amyloidosis and uric acid nephropathy rarely cause hematuria. Amyloidosis occurs most frequently in the elderly and uric acid nephropathy typically occurs in patients with malignancy (leukemia) or gout. (Choices C, E, F, G, and I) Fanconi syndrome (polyuria, acidosis, hypophosphatemia), lead nephropathy (Fanconi-like syndrome), hypersensitivity interstitial nephritis (fever, rash, and renal dysfunction due to drug reaction), renal artery stenosis (hypertension in older patients), and acute tubular necrosis (acute kidney injury due to ischemia or nephrotoxins) are not typically characterized by gross hematuria. (Choice D) Hemolytic-uremic syndrome (microangiopathic hemolytic anemia, thrombocytopenia, acute renal failure) generally occurs 1-2 weeks after a diarrheal illness (classically due to Escherichia coli O157:H7). Educational objective: Renal papillary necrosis classically presents with gross hematuria, acute flank pain, and passage of tissue fragments in urine. It is most commonly seen in patients with sickle cell disease or trait, diabetes mellitus, analgesic nephropathy, or severe obstructive pyelonephritis. __________ References: Sickle cell trait and renal papillary necrosis. (http://www.ncbi.nlm.nih.gov/pubmed/24807983)

A 21-Year-Old Man Comes to the Emergency Department Due to 1