Analysis of CT findings in the different pathological subtypes of primary thyroid malignant lymphoma

CAI Linghong; JIANG Mingxiang; BA Lei; DONG Fei

Abstract：Objective To explore the CT features in the different pathological subtypes of primary thyroid malignant lymphoma (PTML) in order to improve the diagnostic level of this rare disease. Methods The clinicopathological data and CT images of 25 patients with PTML were retrospectively reviewed. Results 1) In the 25 cases,two different pathological subtypes of lymphoma were observed: 13 cases had diffuse large B-cell lymphomas(DLBCL) ,and 12 cases had mucosa associated lymphoid tissue lymphomas (MALT). There were total 35 lesions in 25 patients. The lesions were unilateral in 15 cases,lesions were bilateral in 10 cases,with isthmus involved in 3 cases. The maximum diameter of the lesions ranged from 1. 3 to 8. 2 cm. The average maximum diameter was (4. 0 ± 0. 3) cm,of which the maximum diameter of DLBCL and MALT was (2. 3 ± 0. 4) cm,(4. 7 ± 0. 6) cm respectively; 2) Of the 35 lesions,5 were round,13 were oval round and 17 were lobular,most of which were seen in the DLBCL. 14 lesions showed smooth edge (12 MALTs,2 DLBCLs) and 21 lesions (21 DLBCLs) demonstrated foggy edge. 15 lesions (12 MALTs,3 DLBCLs) manifested complete envelope and 20 lesions (20 DLBCLs) manifested imcomplete envelope which invaded the surrounding tissue and organs; 3) 27 lesions manifested as low-density and 8 lesions manifested as isodensity without obvious hemorrhage and calcifications on non-enhanced CT. The CT densities were homogeneous in 29 lesions (12 MALTs, 17 DLBCLs) and heterogeneous in 6 lesions (6 DLBCLs); 4) After intravenous injection of contrast media,17 lesions (7 MALTs,10 DLBCLs) demonstrated mild enhancement and 18(5 MALTs,13 DLBCLs) lesions demonstrated moderate enhancement. Enlarged cervical lymphnodes were found in 8 of 13 cases of DLBCL. Conclusion CT findings of PTML have certain characteristics with both commonness and individuality,and different pathological subtypes of PTML have different CT appearance.