Evaluation of primary thyroid lymphoma by ultrasonography combined with contrast‑enhanced ultrasonography: A pilot study.

ABSTRACT

OBJECTIVE: To evaluate the features of primary thyroid lymphoma (PTL) by ultrasonography (US) combined with contrast‑enhanced ultrasonography (CEUS). MATERIALS AND METHODS: In this retrospective study, 20 patients (8 male and 12 female) with PTL were evaluated by conventional US and among them, 10 patients underwent CEUS examination. The appearance of US features was classified into three types Diffusive mass type, multiple nodular type and mixed type. The CEUS patterns included diffusive homogeneous enhancement and diffusive heterogeneous enhancement pattern. Parameters of CEUS time‑intensive curve were analyzed in primary tumor and involved lymph nodes compared to ipsilateral common carotid artery. RESULTS: Of 20 patients with PTL, 18 presented an enlarging neck mass that grew rapidly with an average duration of 3.2 months, and 17 were associated with Hashimoto’s thyroiditis. In conventional US, all patients had marked hypoechoic masses. Among them, 12 patients were diffusive mass type, 6 were multiple nodular type and 2 were mixed type. For CEUS patterns, 8 were diffusive homogeneous enhancement and 2 were diffusive heterogeneous enhancement. Necrosis areas were showed in diffuse heterogeneous pattern which were hardly seen in conventional US. In the quantitative analysis of CEUS parameters, the time to peak of time‑intensive curve in the primary tumors or involved lymph nodes was longer than that of the ipsilateral common carotid artery (P = 0.004). CONCLUSION: PTL mainly demonstrated as a diffusive mass type with marked hypoechogenecity on conventional US and diffusive homogeneous enhancement pattern on CEUS. And the heterogeneous enhancement pattern is also helpful for detecting necrosis areas of PTL.