[Tracheal carcinoma infiltrating the thyroid gland and mimicking subacute thyroiditis. Contribution of Doppler to differential diagnosis].

In the present case Color Coded Doppler showed a marked increase in vascularization in the right lobe of the thyroid with high systolic velocities (1 m/s). This sign was only doubtful compared with clinical, biological and isotopic data. Because of dramatic laryngeal dyspnea, surgery was conducted which allowed the final diagnosis of thyroid invasion by tracheal epidermoid carcinoma. This demonstrates the particular role of Color Coded Doppler in the management of inflammatory thyroid diseases.