A 54-year-old man comes to the physician due to blood in his urine and abdominal discomfort that occurred 2 days ago. He was moving potted plants around his porch when he started having pain in his abdomen. Afterward, he noticed blood in his urine but says it resolved the following day. He has a history of hypertension. The patient does not use tobacco, alcohol, or illicit drugs. Physical examination shows no abnormalities. CT scan of the abdomen with contrast is shown below.
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Which of the following is the most likely diagnosis?
Autosomal dominant polycystic kidney disease | |
Genetics |
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Clinical |
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Imaging |
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Extrarenal |
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This patient with flank pain, hematuria, hypertension, and multiple renal and hepatic cysts on imaging (smooth, thin walls with nonenhancing cystic fluid) has autosomal dominant polycystic kidney disease (ADPKD). ADPKD is the most common hereditary cause of renal failure in adults and is caused by mutations in the polycystin genes (PKD1, PKD2) that result in progressive cystic enlargement of the kidneys.
Patients often remain asymptomatic until their fourth or fifth decade, when relentless enlargement of the cysts begins to impair renal function; hypertension is often the earliest clinical sign. Stretching of the renal capsule and dilation/rupture of the cysts can result in abdominal/flank pain; cyst rupture can also cause gross hematuria. Renal dysfunction worsens with age, and approximately 50% of adults progress to end-stage renal disease by age 70. Extrarenal manifestations include liver cysts and intracranial aneurysms that may rupture.
(Choice A) Glomerulonephritis can cause hematuria, hypertension, and renal failure but is not associated with cyst formation. Casts are typically visible on urinalysis.
(Choice B) Hydronephrosis can cause hematuria and pain, particularly if associated with an obstructing stone. However, dilation of the ureters and calyces would be expected on imaging.
(Choice C) Nephroblastoma (Wilms tumor) is the most common pediatric renal malignancy but is rare in adults. It typically presents with a painful abdominal mass, hematuria, and hypertension. CT scan demonstrates a solid, heterogenous renal mass with patchy enhancement.
(Choice E) Renal cell carcinoma is the most common renal malignancy in adults and often presents with hematuria, hypertension, and flank pain. However, imaging typically demonstrates solitary renal mass with areas of contrast enhancement and focal necrosis; bilateral cystic changes would be unexpected.
Educational objective:
Autosomal dominant (adult) polycystic kidney disease is caused by mutations in the polycystin genes (PKD1, PKD2), which result in cystic enlargement of the kidneys and progressive renal dysfunction. Clinical features include hypertension, abdominal/flank pain, and gross hematuria; extrarenal manifestations include liver cysts and intracranial aneurysms.