[Clinical features and prognosis of eight patients with splenic diffuse red pulp small B-cell lymphoma]

Objective: To investigate the clinical characteristics, response, and prognosis of splenic diffuse red pulp small B-cell lymphoma (SDRPL) . Methods: Eight cases of SDRPL were diagnosed and treated at Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, between May 2017 and April 2022. Data on the clinical features, laboratory results, bone marrow and spleen biopsy results, response, and prognosis were collected and analyzed. Results: The median age at diagnosis was 54 (42-69) years. Splenomegaly and lymphocytosis were present in all cases, and PET/CT revealed normal to slightly elevated splenic FDG uptake. All cases were in stage Ⅳ, with spleen, peripheral blood, and bone marrow but no proximal lymph nodes involved. The cytoplasm of neoplastic villous cells was abundant, and splenic pathology showed that small homogenous lymphocytes permeated the splenic sinus and splenic cord, and the white pulp atrophied. Immunohistochemistry was not typical, and B-cell markers including CD19, CD20 and CD79α were positive. After a median follow up of 35.5 (4-60) months, 7 cases were alive after splenectomy with or without chemoimmunotherapy. The patient with CCND3 P284A and MYC S146L mutation developed to B-cell prolymphocytic leukemia (B-PLL) 1 month after splenectomy and died at 16 months of follow-up. Conclusion: A rare indolent B-cell lymphoma that primarily affects the elderly, SDRPL. Most patients achieved long-term survival, but the prognosis of patients who progress to B-PLL was poor.