Villous lymphocytes in splenic large B-cell lymphoma with diffuse red pulp infiltration

Excerpt

A 66-year-old woman presented with fever, night sweats, and abdominal fullness for 2 months. A complete blood count showed pancytopenia with WBC 2520 /µL, Hb: 9.9 g/dL, and PLT: 78 × 10³ /µL and 1% villous lymphocytes (panel A) in the blood smear. The serum LDH level was very high, 2340 IU/L. An abdominal computed tomography (CT) scan revealed a huge spleen (22 cm) with a few small mesenteric lymph nodes (< 1 cm, panel B). The resected spleen (1370 gm) had a homogenous cut surface. Microscopically, there was diffuse red pulp infiltration by medium-sized-to-large lymphocytes (panel C) shown by immunohistochemistry to be positive for CD20, CD79a (panel D), PAX5, Bcl-2, Bcl-6, and CD5 and with a Ki-67 index of 80% (panel E). The lymphocytes were negative for DBA.44, MNDA, CD10, IgD, CD23, LEF-1, cyclin D1, SOX11, CD25, CD123, Annexin A1, and BRAF-V600E. Although villous lymphocytes were observed, the high proliferative index supported a diagnosis of large B-cell lymphoma. The post-operative course was uneventful, and adjuvant chemotherapy was scheduled. The blood examination revealed no more villous lymphocytes. Unfortunately, neck, axillary, and inguinal lymphadenopathy developed 2 months after splenectomy. A follow-up positron emission tomography (PET)-CT showed additional para-aortic lymphadenopathy with high FDG uptake (panel F). Pathology confirmed infiltration of large cell lymphoma with the same immunophenotype. The lesion proved to be refractory, and the patient died in Aug. 2018, 9 months after diagnosis. …