Anatomical variations of the pen process (PS) and ossification of the pen-hyoid ligament constitute Eagle syndrome. This is a rare syndrome, often bilateral, that summarizes the clinical manifestations due to an excessive length of the pen process that is greater than 25mm. Other important morphometric and topographical variations are associated with this anomaly.

Taking these anatomical data into account is essential for the etiopathogenic analysis and surgical treatment of Eagle syndrome. The purpose of this work was to investigate anatomical variations of the pen process during Eagle syndrome.

Material and method:  This was a retrospective study over a period of 07 months from December 2020 to June 2021 inclusive. It concerned 32 patients, received in the radiology and medical imaging department of the National Pikine Hospital for suspicion of Eagle syndrome confirmed by scanner without and with injection. Patients who had a normal scanner were not included in the study. We used SPSS 24.0 and Excel 2016 to analyze the data.

Results:  24 women (75%) and 8 men (25%), a sex ratio of 0.33. The average age of patients was 39 years, with a standard deviation of 12 years, and extremes of 21 to 71 years. The age range of 30-40 was 34% and 41-50 was 33%. Examination found pharyngeal foreign body sensation in 65% of cases, dysphagia in 67% of cases, headache in 71% of cases, and cervical neuralgia. Brachial in 95% of cases. At CT, the average length of all pen processes was 39.2 mm (extremes: 21-76 mm). The elongation of the pen process was bilateral in 68%, unilateral right in 7% of cases, and unilateral left in 25% of cases. Morphologically, the PS consisted of a single long fragment in 78% of cases (Langlais types 1), or two fragments articulated either by fibrous tissue or by a pseudo articulation with an angular shape in 19% of cases (Langlais types 2), or several fragments (3% Langlais types 3).

Conclusion: Eagle syndrome is a radio anatomical entity with several variants whose knowledge is essential to its management.