[Papillary thyroid carcinoma metastasis to parapharyngeal lymph nodes: interest of the PET scan]. / Métastase ganglionnaire parapharyngée d'un carcinome papillaire thyroïdien. Intérêt du TEP scan.

UNLABELLED: Thyroid cancer rarely metastasizes to the parapharyngeal space. A inconsistent lymphatic drainage pathway is involved, as described by Rouvière. OBJECTIVES: To demonstrate the interest of [18 F]-FDG PET in early diagnosis of metastasis and in the follow up of the patient. MATERIAL AND METHOD: 40 y.o. male with papillary carcinoma who had a secondary parapharyngeal metastasis. The diagnosis of recurrence was difficult, as the plasmatic thyglobulin was low, and the iodine scan was not informative. In this case, [18 F]-FDG PET-CT was informative (clear parapharyngeal fixation) and led to the diagnosis of recurrence. CONCLUSION: It appears that 18F FDG PET has a good diagnostic value and that its sensitivity is better than CT scan and MRI. Some authors recommend the use of [18 F]-FDG PET and scintigraphy with Iodine 131 to screen patients with thyroid cancer recurrences.