[Lymphoplasmacytic lymphoma: a clinicopathological and prognostic analysis of 27 cases]

Objective: To study the clinical manifestations, pathologic features, diagnosis and differential diagnosis, treatment and prognosis of lymphoplasmacytic lymphoma/Waldenström's macroglobulinemia (LPL/WM). Methods: Twenty-seven cases of LPL from January 2016 to December 2020 at Guangdong Provincial People's Hospital were collected. The clinical data, histomorphology, immunophenotype, MYD88 L265P mutation, treatment and prognosis were analyzed retrospectively. Results: There were 19 males and 8 female patients, with median age of 63 years. The most common initial symptoms were fatigue related to anemia. Bone marrow was involved in all cases, lymphadenopathy was seen in 11 cases and splenomegaly in 10 cases. Monoclonal IgM type protein was detected in 25 cases, meeting the diagnostic criteria of WM. Microscopically, bone marrow and lymph nodes were infiltrated by small lymphocytes, plasmacytoid lymphocytes or plasma cells. The cells expressed pan B-cell markers and showed immunoglobulin light chain restriction. There was no expression of CD5, and low expression of CD23 and CD10; Ki-67 index was usually low. The positive rate of MYD88 L265P mutation was 73.9% (17/23). Most of the patients were treated with rituximab combined with alkylating agents, nucleoside analogues or immunomodulators, and the few patients with relapse or progression were treated with Ibutinib. During the 3-168 months' follow-up period, recurrence or progression were seen in nine cases. Thrombocytopenia, elevated β2-microglobulin and high-risk group were associated with recurrence or progression of the disease (P<0.05). The overall survival (OS) and progression-free survival (PFS) of the high-risk patients were significantly lower than those of the low-medium risk patients (P<0.05). Conclusions: LPL/WM is an exclusive diagnosis; the detection of MYD88 L265P mutation has high diagnostic value, but it is not specific. These cases should be assessed comprehensively for their clinical manifestation, serum IgM protein level and immunophenotype. The overall prognosis of LPL/WM is good, but there are still a small number of high-risk patients with rapid progress, and so the symptomatic patients should be diagnosed accurately and treated in a timely manner.