Objective  To explore the sonographic findings of primary thyroid lymphoma (PTL) and evaluate the role of ultrasound-guided core-needle biopsy in diagnosing this disease.

  Methods  The clinical data, sonographic, and biopsy modes of 22 patients (age range, 32-81 years; median, 61 years) with pathologically confirmed PTL were retrospectively analyzed. The sonographic findings of PTL were divided into three types:diffuse type, nodular type, and mixed type.

  Results  The main pathologic types of PLT in these 22 patients included mucosa-associated lymphoid tissue lymphoma (n=10, 45.5%) and diffuse large B-cell lymphoma (n=8, 36.4%). In 16 patients (72.7%), the initial symptom was enlarged neck mass. Among the 22 patients with a diagnosis of PTL, 16 (72.7%) were sonographically diagnosed as malignancies or suspected malignancies and 6 (27.3%) as benign lesions. In 10 patients who had received ultrasound-guided fine-needle aspiration biopsy, only 2 were diagnosed as suspected malignancies. In 9 patients who had received ultrasound-guided core-needle biopsy, 8 (88.9%) achieved definitive pathological diagnoses. In 15 patients who had undergone surgical biopsy, pathological diagnoses were obtained in all of them. The distribution of the sonographic findings of PTL was asfollows:diffuse type, n=10 (45.5%); nodular type, n=9 (40.9%); and mixed types, n=3(13.6%).

  Conclusions  Ultrasonography is helpful for PTL diagnosis, especially in patients with rapid thyroid enlargement. Ultrasound-guided core-needle biopsy is safe and accurate, and therefore remains a preferred method for diagnosing thyroid lymphoma.