From the Guidelines
Hyaline casts with flank pain are highly suggestive of a kidney stone, and immediate medical evaluation is necessary to rule out urolithiasis and its potential complications, such as ureteral obstruction and hydronephrosis, as suggested by the most recent study on acute onset flank pain-suspicion of stone disease 1. The presence of hyaline casts in urine, accompanied by flank pain, is a significant clinical finding that requires prompt attention. According to the latest guidelines on acute onset flank pain-suspicion of stone disease, published in the Journal of the American College of Radiology in 2023 1, the incidence of kidney stones increases with age, and men are more commonly affected than women.
- Key points to consider in the diagnosis and management of hyaline casts with flank pain include:
- The possibility of ureteral hyperperistalsis and ureteral obstruction, which can lead to severe complications such as hydronephrosis and renal damage 1
- The importance of imaging studies to confirm the diagnosis of urolithiasis and rule out other potential causes of flank pain, such as infection or other renal pathologies 1
- The need for supportive care, including pain management and hydration, to help manage symptoms and prevent further complications
- The potential need for invasive therapies, such as percutaneous nephrolithotomy, rigid and flexible ureteroscopy, or shock wave lithotripsy, in cases where the stone is large or proximally located and unable to pass spontaneously 1 The clinical presentation of hyaline casts with flank pain is nonspecific and can be associated with various other entities, but the latest evidence suggests that urolithiasis should be considered as a potential cause, and imaging studies should be performed to confirm the diagnosis and guide management 1.
From the Research
Hyaline Casts and Flank Pain
- Hyaline casts in urinary sediments can be an indicator of kidney diseases, but they can also be found in patients without renal dysfunction, particularly those with cardiovascular issues 2.
- The presence of hyaline casts in patients with normal renal function may suggest increased plasma brain natriuretic peptide (BNP) levels 2.
- Flank pain can be caused by various urinary and extraurinary abnormalities, with ureterolithiasis being a common cause 3, 4, 5.
Diagnostic Approaches
- Unenhanced helical CT (UHCT) is a highly sensitive and specific imaging modality for evaluating acute flank pain, detecting ureteral stones with a sensitivity and specificity of 98-100% regardless of size, location, and chemical composition 3, 5.
- Ultrasonography (US) can also be used to evaluate acute flank pain, with a sensitivity of 72-83.3% for detecting hydronephrosis, and can help exclude other serious causes of flank and abdominal pain 4, 6.
- Point-of-care ultrasound (PoCUS) can be a useful tool in the emergency department for identifying renal causes of flank and abdominal pain, resulting in more rapid diagnosis and decreased use of computed tomography 6.
Clinical Implications
- The detection of hyaline casts in patients with flank pain should prompt further evaluation, including assessment of plasma BNP levels and imaging studies to rule out underlying kidney diseases or other causes of flank pain 2.
- A modern approach to diagnosis and management of acute flank pain should involve a combination of clinical evaluation, laboratory tests, and imaging studies, including UHCT and US, to rapidly and accurately determine the cause of pain and guide treatment 3, 4, 5.