Clinicopathological features of splenic tumours of lymphoid tissue

Background: To study the effects of splenectomy on treatment and diagnosis of tumours of lymphoid tissue of the spleen.

Methods: Fifty-three cases were reviewed from Peking University People's Hospital from 2002 to 2017. According to WHO classification of tumours of haematopoietic and lymphoid tissues (2008) and classification updated (2016), the cases were studied by microscopy, immunohistochemistry and in situ hybridization, combined with the bone marrow biopsy and clinical examination.

Results: In 53 cases, the male to female ratio was 3.4:1, the mean age was 55.4 years old, the median survival time was 17.0 months, and all patients present with variable degree of splenomegaly. The elevated percentage of lymphocyte in peripheral blood can be seen in 22 cases, and elevated LDH level in 24 cases. Abnormal blood counts can be seen in 26 cases before operation, and 22 cases remission to normal level partly or completely after operation. The clinical symptoms included abdominal pain or distension, fatigue, fever, and weight loss, etc. Seventeen cases present with lymphoadenopathy of abdomen or other sites. Fourteen cases were stage I or II, whereas 6 were stage III, 28 were stage IV. Forty-three cases were splenic B-cell marginal zone lymphoma (SMZL)(48.8%,21/43), DLBCL(23.3%,10/43), splenic diffuse red pulp small B-cell lymphoma (SDRPSBL)(11.6%,5/43), mantle cell lymphoma (MCL)(9.3%,4/43), follicular lymphoma (FL)(4.7%,2/43), composite lymphoma (CL, DLBCL and classical Hodgkin lymphoma)(2.3%,1/43) in turn, and the remaining 10 cases were chronic lymphocytic leukaemia/small lymphocytic lymphoma (CLL/SLL) (n = 4), hairy cell leukaemia (HCL) (n = 1), hepatosplenic T-cell lymphoma (HSTL) (n = 5). The survival period of SMZL and DLBCL was 25.7, 18.6 months, respectively. Thirteen cases were dead (27.1%, 13/48). The chemotherapy protocol included Hyper-CVAD A/B with/without R (Rituximab), COP, CHOP with/without R etc. The prognosis of those with elevated LDH level, high clinical staging, B symptom, and older than 60 year old was obviously worse, and the prognosis of DLBCL was worse than that of SMZL.

Conclusions: Most splenic lymphoid tumors present with splenomegaly and abnormal blood counts, and complete or part remission of blood counts can be seen after splenectomy, and splenectomy is also helpful for pathological diagnosis. The most common pathological types are SMZL and DLBCL. The definite diagnosis can be made by combining with clinical features, histopathology, immunophenotype, genetics, bone marrow biopsy and laboratory examination.