A patient with conventional and follicular variant papillary thyroid microcarcinoma and Eagle's syndrome, Langlais type III, with hyoid bone variation.

Aim: Presenting an extraordinary case of Eagle's syndrome (ES) with the classical and follicular variant of papillary thyroid microcarcinoma (PTmC) and an uncommon stylohyoid ligament calsification, aside from O'Carroll's System.

Case Report: A 52-year-old Turkish man with an histopathology of the follicular variant of PTmC (FVPTmC) of his right lobe and conventional PTmC of his left lobe of the thyroid with an adjuvant 100 mCi radioactive iodine (RAI) ablation was admitted. On the routine follow-up of the present case, a lineer structure at the 3rd compartment of neck in his ultrasonography, a styloid ligament calsification in his noncontrast computed tomography (CT), and a left styloid process of the temporal bone of 29 mm in size in his three-dimensional (3D) CT scanning had been revealed. Conclusively, an ES, Langlais Type III with The Calcification Pattern IV, was recognized.

Discussion: A noninvasive peroral medical management was administered as a first-line treatment for the neuropathic sequelae of ES and it has provided relief of signs and symptoms without any recurrence to date, for three years and three months.

Conclusion: To our knowledge, it is an highly extreme and first case of ES in the English literature, recognized in the course of his programmed follow-up of his conventional PTmC and FVPTmC, simultaneously possessing an exceptional stylohyoid ligament calsification, apart from O'Carroll's System, even with an anatomic variation of the hyoid bone.

Key Words: Eagle's Syndrome Follicular variant of papillary thyroid microcarcinoma, Hyoid bone variation, Langlais classification, O'Carroll's System, Radioactive iodine, Papillary thyroid microcarcinoma.