nephro q2 not nbme - newbiemd

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A 50-year-old man has renal cystic disease. At age 19 years he was found to have hematuria and 1+ proteinuria on urinalysis. At age 29 years he was found to have hypertension and proteinuria. At age 34 years he had ultrasonography for gross hematuria, which showed normal to small-sized kidneys, two cysts in the right kidney, and one cyst in the left kidney, the largest of which was 2 cm.

He has no family history of premature deaths or renal disease. Physical examination is remarkable only for a blood pressure of 170/110 mm Hg and 1+ pedal edema. Laboratory studies show a serum creatinine of 3.0 mg/dL and 24-hour urinary protein excretion of 3.0 g. Urinalysis shows 3+ proteinuria and 5 to 10 erythrocytes per high-power field without casts. Repeat ultrasonography shows small-sized kidneys, two cysts in the right kidney, and one cyst in the left kidney, the largest of which is 2.5 cm.

Which of the following is the most likely diagnosis?

( A ) Autosomal dominant polycystic kidney disease
( B ) Medullary cystic disease
( C ) Acquired cystic disease
( D ) Tuberous sclerosis
( E ) Multiple simple cysts

[ArchivalUser]

a.

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[ArchivalUser]

c.

[ArchivalUser]

c
Because of the use and the sensitivity of ultrasonography, renal cysts are often detected in the course of evaluation of renal disease and other abdominal disorders. Autosomal dominant polycystic kidney disease (ADPKD) needs to be considered in any patient with bilateral renal cystic disease and renal insufficiency. The lack of family history does not exclude the diagnosis, because only 60% of patients have a positive family history. The paucity of positive family history reflects the fact that the diagnosis is often not made in the previous generation, rather than a high rate of spontaneous mutation.

Although the history of microscopic and gross hematuria and hypertension is compatible with ADPKD, the normal-sized kidneys and the paucity of cysts when renal insufficiency is present weigh very heavily against ADPKD. In addition, in ADPKD, proteinuria in the nephrotic range is rare, and patients with heavy proteinuria who have had a renal biopsy have been found to have another glomerular renal disease.

This patient™s age, only slightly small kidneys with renal cysts, and nephrotic-range proteinuria make medullary cystic disease exceedingly unlikely. Acquired cystic disease is well known to occur before the advent of dialysis, particularly in long-standing renal disease. Men are more susceptible than are women. This man has a 20-year history of hematuria, proteinuria, and hypertension. The paucity and relatively small size of cysts and the lack of renal enlargement also are compatible with this diagnosis.

The absence of any other extrarenal findings and the lack of renal adenomas weigh against tuberous sclerosis. Multiple simple cysts are always a consideration in such a patient, and there is no test that absolutely excludes this diagnosis. However, the simple cysts increase with age, are most common after age 50 years, and are most often single and unilateral. However, this man had multiple, bilateral cysts at age 34 years, which weighs against this diagnosis.

Distinguishing ADPKD from acquired cystic disease is important. Patients with ADPKD require family counseling, and because this disorder is systemic, physicians should consider the possibility of other organ abnormalities. Acquired cystic disease is associated with increased potential for malignancy, also an important reason for differentiating this disorder from multiple simple cysts.

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thnaks nice q