ABSTRACT
Purpose To investigate the clinical-pathological characteristics of the primary thyroid intravascular large B-cell lymphoma (PT-IVLBCL). Methods The clinical-patho-logical data of the PT-IVLBCL were analyzed retrospective. A comprehensive analysis of the literature on IVLBCL published between 1991-2017 in China were performed. Results A thy-roid mass was identified in a physical examination of a 68-year-old male who initially presented with dyspnea accompanied by intermittent headache for about 1 month. Pathological results showed that large atypical lymphoma-like cells filled the small vessel capillaries in the lesion area. Immunohistochemical staining revealed that the lymphoma-like cells were positive for CD20, Pax-5, BCL-2 and MUM1. The Ki-67 index was estimated to be approximately 85％. Conclusion IVLBCL is a rare and aggressive disease that is easy to be misdiagnosed or missed, because it's clinical presentations are non-specific. The correct diagnosis depends on pathology. IVLBCL is known for its rapid progression and poor prognosis, but timely diagnosis and treatment with chemotherapy can improve patients survival.