Imaging description

An 11-year-old boy presented with end-stage renal disease (ESRD). A radiograph of the abdomen demonstrated multiple focal calcifications, projecting over the bilateral kidneys (Fig. 66.1a). An ultrasound confirmed echogenic calcifications in the deep parenchyma of the kidneys bilaterally, consistent with medullary nephrocalcinosis (Fig. 66.1b). An X-ray of the left hand showed dense metaphyseal bands on the metaphyseal side of the growth plates of the radius and ulna as well as focal cystic rarefactions and sclerotic margins of the metaphyses of the radius and ulna (Fig. 66.1c).

Importance

Oxalosis is a condition in which calcium oxalate crystals are deposited in renal and extrarenal tissues. The underlying pathology is hyperoxaluria, excessive oxalate excretion in the urine (> 40 mg/mL), which leads to chronic renal failure. Once oxalate cannot be excreted due to impaired renal function, insoluble calcium oxalate crystals are deposited in bone, bone marrow, blood vessels, central nervous system, peripheral nerves, retina, skin, and thyroid.