Acute Calcific Retropharyngeal Tendinitis with Eggshell-like Calcification: Case Report and Literature Review on Time-course Changes in Imaging Findings

Acute calcific retropharyngeal tendinitis is a rare disease, and few studies have reported the radiological findings of its time-course in detail. These radiological findings vary according to the calcific stage. We report a case of acute calcific retropharyngeal tendinitis with eggshell-like calcification detected on follow-up computed tomography (CT). We also review pertinent literature on calcific retropharyngeal tendinitis, with a focus on time-course changes in imaging findings. A 54-year-old Japanese woman presented with acute severe neck pain. She also had a limited range of motion in the rotation of her neck and moderate pain and discomfort during swallowing. Plain radiographs of the cervical spine showed no apparent abnormality. CT revealed massive retropharyngeal calcification in front of the C1-C2 vertebrae. The patient was diagnosed with acute calcific retropharyngeal tendinitis and treated with a soft collar and non-steroidal anti-inflammatory drugs. Two weeks later, the neck pain and dysphagia improved. At the one-month follow-up, CT showed residual marginal calcification, which was diminishing in size, suggesting eggshell-like calcification. We believe that although the eggshell calcification appearance is extremely rare, it is important to note this atypical presentation of acute calcific retropharyngeal tendinitis.