Endocrine Abstracts

Background: The management of differentiated microcarcinomas of the thyroid (DMCT) is controversial, and ranges from simple active surveillance to total thyroidectomy with bilateral lymph node dissection and post operative adjuvant therapy. Our purpose was to determine prognostic factors to guide the surgery of DMCT.

Methods: This was a retrospective study conducted from January 2000 to December 2017, involving 122 patients with DMCT who were treated surgically, at the ear nose throat and head and neck surgery and the nuclear medicine departments.

Results: In our population (sex ratio = 0.13), the average age was 46 (range 18 to 84). During the first time of surgery, the extent of the procedure was based on ultrasound and extemporaneous examination results: a non-total thyroidectomy was performed in 10 patients (8%), a total thyroidectomy in 108 patients (89%), and a completion thyroidectomy in 4 patients (3%). The dissection of bilateral central lymph nodes (CLN) was done in 46 patients (38%), of ipsilateral CLN in 2 patients (1.5%), and of bilateral CLN et lateral lymph nodes in 10 patients (8%). After definitive histological examination, a surgical complement was performed in 12 patients (9.8%). At definitive histology examination, a typical thyroid papillary microcarcinoma was observed in 60 patients (49%), a vesicular type of thyroid papillary microcarcinoma in 52 patients (43%), and a thyroid vesicular microcarcinoma in 10 patients (8%). Multifocality was observed in 34 patients (27.9%), an extra-thyroidal extension in 2 patients (1.6%), with a mean tumor size 5.8mm. Histological lymph node involvement was observed in 24 patients (36.4%) among the 66 patients who underwent lymph node dissection. A therapy by I131 was indicated in 100 patients (82%). A complete remission was noted in 76 patients (62.3%). Regional lymph node recurrence was detected in 4 patients (3.2%). No cases of distant metastases or deaths have been reported. The analytical study showed that tumor size and multifocality were statistically significant risk factors for occult lymph node involvement.

Conclusion: The "active surveillance" is retained by several authors as the attitude of choice in case of DMCT without risk factors for locoregional evolution. In the absence of such conditions, surgical treatment remains the gold standard.