10 years old female, mildly increased serum creatinine, “R/O hydronephosis”
Important findings? Dx? Cause(s)?

Related study … U/S of “neck area” Final Dx?

Answers
Medullary Nephrocalcinosis from parathyroid Adenoma

• Medullary Nephrocalcinosis: multiple areas of increases echogenicity involving all of the medullary pyramids; cortex is normal
• Typical parathyroid adenoma: hypechoic, oval, solid mass adjacent to the posterior surface of the thyroid gland

Medullary Nephrocalcinosis – CT Correction

Medullary Nephrocalcinosis: 95% of all nephrocalcinoses. Calcifications involving the distal convoluted tubules in the loops of Henle
Causes:

• Endocrine: Hyperparathyroidism, paraneoplastic syndrome, cushing’s, DI
• Alimentary: Milk-alkali, hypervitaminosis D, beryllium poisoning
• Renal: Medullary Sponge kidney, RTA, Bartter’s syndrome
• Drugs: Lasix, ACTH Rx, Vitamin E, other (e.g., sarcoid)