Differential Diagnosis for Calculi in a 13-year-old Boy
Single Most Likely Diagnosis
- Idiopathic Calcium Oxalate Nephrolithiasis: This is the most common cause of kidney stones in adolescents, often related to dietary factors, hydration, and genetic predisposition.
Other Likely Diagnoses
- Urinary Tract Infection (UTI) with Stone Formation: Certain bacteria can increase the pH of urine, leading to the formation of struvite stones. This is more common in girls but can occur in boys, especially if there's an underlying anatomical issue.
- Hypercalciuria: Excessive calcium in the urine can lead to stone formation. This condition can be familial or secondary to other metabolic disorders.
- Cystinuria: An inherited disorder that leads to the formation of cystine stones due to a defect in the transport of cystine and other amino acids in the kidneys.
Do Not Miss Diagnoses
- Primary Hyperparathyroidism: Although rare in children, this condition can lead to hypercalcemia and subsequent stone formation. It's crucial to diagnose and treat to prevent long-term complications.
- Medullary Sponge Kidney: A congenital disorder that can lead to the formation of small stones within the collecting ducts of the kidneys. It's essential to identify this condition to manage stone recurrence and potential kidney damage.
Rare Diagnoses
- Xanthinuria: A rare genetic disorder leading to the deficiency of xanthine oxidase, resulting in xanthine stones.
- 2,8-Dihydroxyadenine (DHA) Stones: Associated with a deficiency of the enzyme adenine phosphoribosyltransferase, leading to the accumulation of DHA, which can form stones.
- Indinavir Stones: Although more common in individuals with HIV taking indinavir, it's a rare cause of stones in the general population, including adolescents.