Different CT imaging findings between histological subtypes in patients with primary thyroid lymphoma.

PURPOSE: This study evaluates the differences in CT imaging findings between diffuse large B cell lymphoma (DLBCL) and mucosa-associated lymphoid tissue (MALT) lymphoma of the thyroid gland.

METHODS

This study included 18 patients with histopathologically confirmed primary thyroid lymphoma (nine with DLBCL and nine with MALT lymphoma). All patients underwent pretreatment CT imaging. We retrospectively reviewed all images and compared the imaging findings between the two pathologies.

RESULTS

The maximum diameter was significantly greater in DLBCL than in MALT lymphoma (67.7 ± 17.0 mm vs. 41.0 ± 27.2 mm, p < 0.01). Diffuse type (78% vs. 11%, p < 0.01), thickening of the isthmus (78% vs. 22%, p < 0.05), invasion of surrounding tissues (78% vs. 0%, p < 0.01), and regional lymphadenopathy (44% vs. 0%, p < 0.05) were more frequent in DLBCL than in MALT lymphoma. However, preserved peripheral thyroid tissue was more frequent in MALT lymphoma than in DLBCL (78% vs. 22%, p < 0.05).

CONCLUSIONS

The maximum diameter, morphological patterns (diffuse or nodular type), thickening of the isthmus, invasion of surrounding tissues, regional lymphadenopathy, and preserved peripheral thyroid tissue were useful CT imaging features in differentiating DLBCL from MALT lymphoma of the thyroid gland.