Is ultrasonographic evaluation sensitive enough to detect multicentric papillary thyroid carcinoma?

This study aimed to investigate the preoperative ultrasonographic (US) evaluation of multicentric papillary thyroid carcinoma (PTC) and to evaluate the association of US findings with lymph node metastasis and extracapsular extension in PTC.

Preoperative US evaluations of patients with PTC who underwent total thyroidectomy were retrospectively investigated. Pathological perspectives and US features of PTC were analyzed. The sensitivity of US in detecting multicentric PTC was evaluated.

The present study included 89 PTC patients who underwent total thyroidectomy. In total, 164 nodules were detected by preoperative US. Significant differences in US pattern were found between benign and malignant nodules. Of the 89 patients with PTC, 33 (37.08%) cases were confirmed as multicentric PTC by operation and pathological examination, 22 (66.67%) of which were bilateral. Before surgery, only 23 patients were suspected as multicentric PTC based on US findings. Pathological examination revealed that malignant nodules in 17 (51.51%) patients with multicentric PTC had been missed by preoperative US. The malignant nodules that went undetected by US were micronodulars (1-4 mm). Furthermore, ultrasonography was less sensitive for the diagnosis of metastatic lymph nodes in the neck. US had more than 80% sensitivity for detection of extracapsular extension of cases.

US evaluation is not sensitive enough to detect multicentric PTC. The minute size of some nodules in multicentric PTC, may lead to them being missed by US evaluation. Ultrasonography is an optional tool for the detection of extracapsular extension, but it is less sensitive for diagnosing lymph node metastasis.