The value of lymph node size and distribution in ipsilateral central lymph node of single papillary thyroid carcinoma in CT examination

Objective To investigate the diagnostic value of lymph node size and distribution in ipsilateral central lymph node metastasis (ICLNM) of single papillary thyroid carcinoma (PTC) in CT examination. Method The CT data of 278 single PTC with diameter > 1.0 cm confirmed by operation and pathology were retrospectively analyzed. According to the ipsilateral central lymph node diameter, these cases were divided into < 0.2 cm group, 0.2-0.4 cm group and ≥0.4 cm group, and the distribution difference of ICLNM positive and negative between the three groups were analyzed. Then according to the lymph node distribution, 0.2 to 0.4 cm group were divided into turbidity group (≥3) and non-turbidity group (1-2) , and ≥0.4 cm group were divided into cluster group (≥3) and non-cluster group (1-2) . The differences betweeen turbidity group and non-turbidity group, cluster group and non-cluster group were analyzed. Results In 278 PTC, the proportion of ICLNM positive and negative was 65.8% (183/278) and 34.2% (95/278) , respectively. ICLNM positive in <0.2 cm group, 0.2-0.4 cm group and ≥0.4 cm group accounted for 37.3% (31/83) , 68% (66/97) and 87.8% (86/98) , respectively. χ2 value and P value in between groups and within groups were 51.082 and 0, 16.956 and 0, 49.955 and 0, 11.022 and 0.001, respectively. ICLNM positive in turbidity group and non-turbidity group accounted for 74.0% (57/77) and 45% (9/20) , respectively. χ2 value and P value were 6.151 and 0.013, respectively. ICLNM positive in cluster group and and non-cluster group accounted for 92.6% (50/54) and 82% (36/44) , respectively. χ2 value and P value were 2.619 and 0.106, respectively. Conclusions Among CT examination of patients with PTC, with the increase of the diameter and number of lymph nodes in central group, the positive proportion of ICLNM positive increases. For the 0.2-0.4 cm group, the turbidity phenomenon suggests that the possibility of metastasis is greater. The accurate identification of these signs can help surgeons take a more thorough surgical treatment and have great significance to reduce postoperative recurrence. Key words: Thyroid neoplasms; Thyroid nodule; Central lymph node; Tomography; X-ray computed