By combing through 2,363 cases of papillary thyroid microcarcinoma (PTMC), the Department of Ultrasound, PUMCH singled out three signs indicating higher possibility of PTMC returning. They are: microcalcification of primary tumor, the largest diameter is more than 7mm, and huge metastasis in central lymph node in patients with capsular invasion. The research is of great value in PTMC diagnosis and choice of therapies and won first prize at 2017 Beijing Medical Association Ultrasound in Medicine Annual Meeting and third prize of 2017 Medical Achievement Award, PUMCH.

PTMC refers to papillary thyroid carcinoma with the largest diameter less than 1cm. It is commonly seen clinically and most of them are of good prognosis, but the risk of metastasis and recurrence cannot be ruled out. Ultrasound on thyroid and neck lymph nodes is an important reference in prognosis assessment, choice of surgery and the surgical scale. Ultrasound is powerful in showing thyroid and side lymph nodes but its accuracy is less than 50% on central lymph nodes as affected by gas, bones and glands. If metastasis is found in more than five lymph nodes, it is defined as huge lymphatic metastasis. Researches showed a high relation between huge lymphatic metastasis and PTMC recurrence. The American Thyroid Association (ATA) in its 2015 Thyroid Carcinomia Guidelines has listed huge lymphatic metastasis as an important risk factor of PTMC recurrence.

Relying on a multidisciplinary team, our Department of Ultrasound used ultrasound images, pathological and surgical data bank and summed up 2,363 PTMC cases of clear diagnosis, complete medical records and clear lymphatic metastasis. Through single and multiple factor regression analysis on the ultrasound features of huge and non-huge lymphatic metastasis, it established the relation between ultrasound features of primary tumor and huge metastasis in central lymph nodes. There is a higher risk of huge central lymphatic metastasis in males under 45, with microcalcification of primary tumor, when the largest diameter is more than 7mm and with capsular invasion.  

According to Xia Yu, deputy director of the Department of Ultrasound, this research indicates that ultrasound doctors should closely examine the central lymph nodes of patients with suspected PTMC, when the largest diameter is more than 7mm, with microcalcification of primary tumor and with capsular invasion, so as to provide reliable reference for the choice of surgical procedures.