Acute calcific prevertebral tendinitis.

Acute calcific prevertebral tendinitis, also known as retropharyngeal calcific tendinitis and longus colli tendinitis, is an uncommon benign condition presenting as acute neck pain.Typical characteristics of this entity are calcifications at the superior insertion of the longus colli tendons at C1-C2 level and a fluid collection in the retropharyngeal space. Differential diagnosis consists of retropharyngeal abscess, traumatic injury or infectious spondylitis. Knowledge of the clinical and imaging findings can prevent misdiagnosis with inappropriate attempts at surgical drainage.