A 30-something year old male presents with left-sided neck pain of relatively acute onset. He is in significant discomfort, and endorses that he has not been eating well because swallowing exacerbates the pain. He appears uncomfortable upon head turning. There is no history of trauma. You are concerned enough to get a neck CT which shows the following:
What is your differential diagnosis? What would you do next? Scroll down for the Case Conclusion.
Final Diagnosis: Acute Calcific Tendonitis of the Longus Colli
Case Conclusion: The patient was transferred to BJH out of concern for infection of the cervical vertebrae. Radiology reviewed the imaging and he was ultimately diagnosed with acute calcific tendonitis of the longus colli. He was discharged on a course of NSAIDs. On follow-up with theSpine service two week later, the patient was doing well and his symptoms had resolved.
Learning Points: Acute calcific tendonitis of the longus colli muscle (LCT) is an inflammatory condition caused by deposition of calcium hydroxyapatite crystal in the superior tendon fibers of the longus colli muscle. The longus colli muscle is a paired muscle that acts as a weak neck flexor. The muscle originates from the bodies of C3-C7 and T1-T3 vertebrae and inserts along the bodies of the C2-C4 and anterior tubercles of C1-C6 vertebrae.
In acute calcific tendonitis, calcium hydroxyapatite deposition leads to a foreign body inflammatory response . This inflammation can lead to accumulation of retropharyngeal fluid, low-grade fever, leukocytosis, and elevation of non-specific inflammatory markers such as ESR . LCT is related to other more common forms of calcific tendonitis affecting the shoulder (supraspinatus tendon), wrist flexors (flexor carpi ulnaris), hip (gluteus maximus) and ankle (longus coli) .
LCT is a rare diagnosis that usually presents in the 3rd to 6th decade of life. Patients present with a relatively acute onset of neck pain and stiffness over several days. The pain is usually associated with difficulty or pain with swallowing and pain with neck movement. The precipitating etiology is unclear. As with this case, the presentation is often concerning for an acute infectious process such as retropharyngeal infection or infectious spondylitis. Unlike either of these more serious diagnoses, the natural course of LCT is spontaneous improvement over a period of 1-2 weeks.
Clinically, the most important pearl about LCT is to avoid mistaking it for a more serious etiology and risking unnecessary invasive intervention. The radiologic diagnosis of LCT is best made with a contrast CT of the neck which demonstrates tendinous calcium deposition in the superior portion of the longus colli. The calcium deposition can be subtle, but usually has a globular amorphous appearance as seen in this patient (arrows below).
The radiologic features of LCT that distinguish it from retropharyngeal abscess or infectious spondylitis include :
- Calcification in the superior tendon fibers of the longus colli muscle.
- Presence of Fluid in the retropharyngeal space without associated ring enhancement which would suggest abscess formation.
- Absence of suppurative or non-suppurating inflammatory retropharyngeal lymph nodes
- Absence of bony destructive change in the adjacent cervical vertebrae
Diagnoses not considered are never made. Every once and awhile, it’s worth considering zebras when evaluating for the worst case scenario.
Case Conclusion by Maia Dorsett (@maiadorsett)
Ellika, S. K., Payne, S. C., Patel, S. C., & Jain, R. (2014). Acute calcific tendinitis of the longus colli: an imaging diagnosis. Dentomaxillofacial Radiology.
 Hall, F. M., Docken, W. P., & Curtis, H. W. (1986). Calcific tendinitis of the longus coli: diagnosis by CT. American Journal of Roentgenology, 147(4), 742-74.
 Offiah, C. E., & Hall, E. (2014). Acute calcific tendinitis of the longus colli muscle: spectrum of CT appearances and anatomical correlation. The British journal of radiology.