What condition is characterized by bilateral flank pain, CVA tenderness, and a positive urine sodium cyanide-nitroprusside test?

What condition is characterized by bilateral flank pain, CVA tenderness, and a positive urine sodium cyanide-nitroprusside test?

• A. Ureteral obstruction
• B. Cystine nephrolithiasis
• C. Renal cell carcinoma
• D. Acute pyelonephritis

Answer: (B)

The condition characterized by bilateral flank pain, CVA (costovertebral angle) tenderness, and a positive urine sodium cyanide-nitroprusside test is cystine nephrolithiasis, which is associated with the presence of cystine stones in the urinary tract. Cystine nephrolithiasis occurs due to a genetic disorder known as cystinuria, which leads to impaired reabsorption of cystine in the renal tubules. As a result, increased levels of cystine in the urine can lead to the formation of crystals and stones, causing symptoms such as flank pain and tenderness, particularly if the stones obstruct the urinary tract. The urine sodium cyanide-nitroprusside test specifically helps to identify the presence of cystine in urine. When cystine is present, it reacts with nitroprusside in the presence of cyanide to produce a significant color change, thus confirming the diagnosis of cystine stones. Understanding these clinical findings and the significance of the urine test is crucial in differentiating cystine nephrolithiasis from other conditions, which may present similarly but do not show this specific urine test result. Cystine nephrolithiasis is distinct in that it is both hereditary and associated

The condition characterized by bilateral flank pain, CVA (costovertebral angle) tenderness, and a positive urine sodium cyanide-nitroprusside test is cystine nephrolithiasis, which is associated with the presence of cystine stones in the urinary tract.

Cystine nephrolithiasis occurs due to a genetic disorder known as cystinuria, which leads to impaired reabsorption of cystine in the renal tubules. As a result, increased levels of cystine in the urine can lead to the formation of crystals and stones, causing symptoms such as flank pain and tenderness, particularly if the stones obstruct the urinary tract.

The urine sodium cyanide-nitroprusside test specifically helps to identify the presence of cystine in urine. When cystine is present, it reacts with nitroprusside in the presence of cyanide to produce a significant color change, thus confirming the diagnosis of cystine stones.

Understanding these clinical findings and the significance of the urine test is crucial in differentiating cystine nephrolithiasis from other conditions, which may present similarly but do not show this specific urine test result. Cystine nephrolithiasis is distinct in that it is both hereditary and associated