Intravascular large B-cell lymphoma involving pleural solitary fibrous tumor: A case report and literature review

Intravascular large B-cell lymphoma (IVLBCL) is a very rare type of extranodal large B-cell lymphoma that selectively grows within vessels and can spread to any organs or tissues. A very few cases of synchronicity with malignant tumor have yet been described. We report a rare case of IVLBCL accompanying a pleural malignant solitary fibrous tumor (MSFT). A 76-year-old man presented with a chronic dry cough, fever, minor general state deterioration and pancytopenia. Imaging revealed a large pleural mass. Histologically, the mass consisted of a MSFT. However, CD20⁺ malignant round cells were scattered within lumina of intratumoral blood vessels, evidencing a synchronous IVLBCL occurrence. Molecular analysis of the lymphoid clone identified MYD88 and CD79B gene mutations. After pleural mass excision, global health’s patient improved with cytopenia correction. However, a general state deterioration appeared 4 months after surgery, associated with a large retroperitoneal mass presenting the same pathological and molecular patterns identical to the initial IVLBCL clone.