Early disappearance of calcification in posterior paraspinal muscles in a patient with rhabdomyolysis associated with neuroleptic malignant syndrome.

We report computed tomography (CT) findings that demonstrated early disappearance of ectopic calcification in the bilateral posterior paraspinal muscles in a patient with rhabdomyolysis. A 37-year-old man with acute renal failure due to rhabdomyolysis caused by neuroleptic malignant syndrome underwent studies with CT and bone scintigraphy. First, bone scintigraphy showed high radiotracer uptake in bilateral posterior paraspinal muscles; then CT demonstrated ectopic calcification in those muscles. After 2.5 months, CT showed that the calcification had completely disappeared. Bone scintigraphy anticipated calcification, and CT demonstrated a unique course of early disappearance of the calcification.