Risk factors for lateral cervical lymph node involvement in follicular thyroid carcinoma.

BACKGROUND: Metastases from follicular thyroid carcinoma (FTC) are usually blood borne and far less to lymph nodes (LN). The present study was designed to evaluate the factors that are associated with LN metastases in patients operated on for FTC. METHODS: A retrospective review of 70 patients (25 men; mean age, 47 (range, 14-92) years) operated on between January 1995 and December 2005 for FTC was undertaken. All patients had histopathology study of the regional LN and postoperative radioiodine scintigraphy. According to LN invasion, they were divided into two groups in which various parameters were compared. RESULTS: The length of follow-up was 52 (range 17-108) months. A total of 375 LN were examined from ipsilateral neck side and 87 LN from the contralateral side. LN metastases were found in five (7%) cases: all ipsilateral. Comparing data from the patients with and without LN metastases, respectively, age was 60 and 47 years (p = 0.12), male/female ratio was 1/4 and 24/41 (p = 0.44), tumor size was 68 and 37 mm (p < 0.01), tumor differentiation (well/moderate) was 3/2 and 25/19 (p = 0.89), distant metastases were detected in 1 and 8 cases (p = 0.72) .The tumor size was >40 mm in 35 (50%) patients. All patients with LN metastases were found in this group (5/35; 14%). CONCLUSIONS: Follicular thyroid carcinoma results in metastases to regional lymph nodes in 7% of cases but only to the ipsilateral neck side. Tumor size is the only factor that impacts it. We do not recommend lymph node dissection in follicular thyroid carcinomas <4 cm.