Milk of calcium is a viscous colloidal
suspension of
calcium carbonate,
calcium phosphate, or
calcium oxalate, or a mixture of these compounds. The calcific material gravitates to the dependent portion of a cystic cavity. Crescent- or hemisphere-shaped
calcium density with a sharp horizontal upper border at the
milk of calcium-clear fluid interface confirms the diagnosis. Bilateral
milk of calcium in the renal pelvis or in dilated calyces is very rare and has not been reported in patients with
spinal cord injury. A 63-year-old male patient with T-10
paraplegia presented with recurrent
urinary tract infections. X-ray of the kidneys, taken with the vertical beam while the patient lay supine, revealed a poorly defined opacity overlying the lower pole of the right kidney. Findings on ultrasonography of the kidneys were interpreted as a large, staghorn-type
calculus in the dilated lower pole calyx of the right kidney. Because x-ray of the kidneys showed a poorly defined opacity overlying the lower pole of the right kidney,
milk of calcium was suspected, and computed tomography (CT) of the kidneys was performed. Calcific debris with horizontal layering in the lower pole calyces of both kidneys was seen; this confirmed the diagnosis of
milk of calcium. A 62-year-old female patient with C-7
tetraplegia underwent
ileal conduit urinary diversion. Subsequently, she developed
calculi in the right kidney, which were treated with
shock wave
lithotripsy. Follow-up x-ray revealed faintly opaque shadows with indistinct margins in the region of both kidneys. Intravenous urography showed
cortical thinning at the upper poles and blunting of the calyces, suggestive of chronic
pyelonephritis. The right renal pelvis was bulky, and bilateral
renal calculi were diagnosed during ultrasonography; however, the presence of faintly
radio-opaque shadows with indistinct margins raised suspicions of renal
milk of calcium. A CT scan of the kidneys, which was performed in the supine and subsequently in the prone position, revealed gravity-dependent layering of calcific material in the pelves of both kidneys and in the midpole calyces of the right kidney, thus confirming the diagnosis of
milk of calcium. In conclusion, CT scan of the kidneys confirmed the diagnosis of bilateral renal
milk of calcium, a very rare entity in patients with
spinal cord injury. Awareness of typical and unique features of
milk of calcium during imaging enables physicians to recognize renal
milk of calcium and to differentiate it from
nephrolithiasis, thereby avoiding unwarranted interventions such as
shock wave
lithotripsy or endoscopic procedures.