[Clinical analysis of lymphocytic thyroiditis coexistent with papillary thyroid carcinoma]

To analyse the clinical features and treatment strategies of papillary thyroid carcinoma(PTC) coexistent with lymphocytic thyroiditis (LT).

A total of 292 patients including 25 males and 267 females with LT and thyroid nodules treated in the department of head and neck surgery between Sep 2011 and Sep 2014 was analysed retrospectively and divided into two groups according to pathological results, of them 262 patients, with a median age of 47 years old, were LT with PTC and 30 patients, with a median age of 54 years old, were LT with benign nodules. Among 262 patients having LT with PTC, 259 were diagnosed as having malignant or suspicious malignant nodules and 3 having benign nodules with ultrasound before surgery, 98 cases were considered multifocal malignant nodules by preoperative ultrasound, and 112 cases were positive in cervical lymph nodes, including bilateral positive in 37 cases. Of 30 patients having LT with benign nodules, 14 were diagnosed malignant or suspicious malignant nodules and 16 benign nodules.

The mean age in 262 patients with PTC was less significantly than that in 30 patients with benign nodules (P<0.05). Ultrasound showed a high proportion of calcification and microcalcification in patients with PTC (34%) compared to patients with benign nodules(13%)(P<0.05). There were not significant differences in the mean levels of serum thyroid stimulating hormone(TSH) (2.80 vs 2.99 mU/L, P=0.233), thyroglobulin(TG) (27.14 vs 18.60 μg/L, P=0.747), and anti-thyroglobulin antibodies(ATG)(417.3 vs 378.7 U/ml, P=0.834) between patients with PTC and those with benign nodules. In patients with PTC, multifocal tumor accounted for 42%. The central and lateral lymph node metastasis rates were respectively 50% and 24%, and the occult metastasis rate of lateral neck lymph node was 16%. Univariate analysis showed that age less than 45 years old, multifocal tumor, tumor diameter more than or equal to 2cm and extrathyroidal extension were associated with central lymph node metastasis (P<0.05), but not with lateral neck metastasis. Multivariate analysis showed a closed correlation only between the lymph node metastases in central and lateral neck levels (P<0.05).

Calcification and microcalcification have the same importance in the ultrasonic diagnosis for PTC in patients with LT. Total thyroidectomy and prophylactic central lymph node should be a choice for LT with PTC. Lymph node metastasis in level Ⅵ indicates the possibility of lateral cervical lymph node metastasis in the patients having LT with PTC.