Medullary nephrocalcinosis

Nephrocalcinosis: by default, we apply this term to ‘medullary’ calcification (= medullary nephrocalcinosis), though it can occur in renal cortex (e.g. in renal cortical necrosis of pregnancy or chronic active glomerulonephritis). Nephrocalcinosis is associated with conditions that cause hypercalcemia, hyperphosphatemia, and increased excretion of calcium, phosphate, and/or oxalate in the urine. Hypocitraturia also may contribute, especially in those with distal (type 1) renal tubular acidosis. Citrate normally inhibits crystal formation by forming a complex with calcium.

Important conditions that cause Medullary nephrocalcinosis: With hypercalcemia + hypercalciuria: primary hyperparathyroidism, sarcoidosis, too much vitamin D. Conditions with hypercalciuria but no hypercalcemia: Distal renal tubular acidosis, medullary sponge kidney, too much furosemide.

On a renal sonogram, the medullary pyramids appear bright or white (hyperechoic) instead of anechoic or hypoechoic. Kidney appears like a stretched chrysanthemum flower. Acoustic shadowing may or may not be seen. Sometimes, the whole pyramid becomes hyperechoic while sometimes it’s only the rim (especially in early stages).

Here is another example with CT scan 3D reconstruction (bone window)

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: