12 cases of primary thyroid lymphoma in China

Primary thyroid lymphoma (PTL) is a rare malignant disease, which can be life threatening because of airway obstruction due to a suddenly and rapidly growing mass. Prompt and accurate detection and diagnosis in the early phase of PTL are crucial for the treatment of this disease. However, due to lack of standardized diagnostic procedures and methods, PTL can be easily missed or misdiagnosed.

In this study, we retrospectively reviewed 12 thyroid lymphomas cases to determine the typical clinical and sonographic profiles of thyroid lymphomas.

All the patients showed symptoms of rapidly developing neck swelling or mass sensation when they underwent diagnostic procedures. We found that, in sonography, 3 of the 12 patients (25.0 %) showed diffuse heterogeneous hypoechoic parenchyma with intervening echogenic septa-like structures, 8 (66.7 %) showed markedly hypoechoic masses, and 1 (8.3 %) showed a mixed pattern. Histological analysis of the lymphomas using paraffin-embedded sections revealed that all the 12 lymphomas were non-Hodgkin lymphoma with a B cell origin: extranodal marginal zone B cell lymphomas of the mucosa-associated lymphoid tissue lymphoma type in 3 (MALT, 25.0 %), and diffuse large B cell lymphomas in 9 (75.0 %) lymphomas. All the MALT patients had diffuse heterogeneous hypoechoic parenchyma in sonography, but only one of them with diffuse large B cell lymphomas had diffuse heterogeneous hypoechoic parenchyma in sonography. Complete remission was achieved in all patients when they were given CHOP or COP therapy accompanied by local radiotherapy after accurate diagnosis of PTL.

We analyzed clinical, sonographic and histological features of twelve cases of malignant lymphoma arising in the thyroid gland and proposed a systematic strategy for prompt and accurate diagnosis of PTL.