Imaging diagnosis of primary thyroid lymphoma and analysis of misdiagnosis

DENG Kaiji; CHEN Ziqian; HU Yongli; CHEN Ping

Abstract：Objective To investigate the imaging features of primary thyroid lymphoma(PTL),and to improve its diagnostic accuracy. Methods The CT manifestations of 6 patients with pathologically confirmed PTL were retrospectively analyzed. Plain CT scan and contrast enhanced scan were performed in 5 patients. MRI scan and 18F-FDG PET/CT scan were performed in 1 pa-tient. Results 6 patients were all found with a thyroid mass. They were all non-Hodgkin lymphoma and 3 patients were with Hashimoto's thyroiditis pathologically. Unilateral thyroid gland involved in 4 cases. Both bilateral lobe and isthmus involved in 1 case. Both unilateral lobe and isthmus involved in 1 case. For the CT fingings,solitary nodule was seen in 2 patients. 1 had mul-tiple nodules. 3 patients had a diffuse goiter. 6 patients had tumors with slight hypodensity. 5 cases presented with homogeneous density. Calcification was shown in 1 case. 5 cases manifested slight or moderate enhancement. 2 cases presented with cervical lymph node invaded. MR findings were lesions with isointensity on T1WI, slight hyperintensity on T2WI, and hyperintensity on DWI. Lesion was hypermetabolic in 18F-FDG PET/ CT imaging. All cases were preoperatively misdiagnosed. Conclusion PTL is easily misdiagnosed and its imaging manifestations have certain characteristics. The accuracy of diagnosis of PTL can be im-proved with a combination of the relevant clinical data. The final diagnosis of PTL depends on pathological examination.