Lymphomas involving the spleen

Splenectomy is undertaken for diagnosis, and in later stages of management, of patients with a diverse range of lymphomas. High quality histological sections, requiring careful attention to tissue fixation, are needed to assess these lesions adequately. Increasing use of fine-needle aspiration, needle core biopsy and laparoscopic surgery add further diagnostic challenges. In addition to involvement by dissemination of lymphomas based primarily in lymph nodes, bone marrow or other tissues, spleen is the predominant site of disease in several distinctive types of lymphoma. In particular, splenic marginal zone B-cell lymphoma, hairy cell leukaemia and T-cell and macrophage-rich large B-cell lymphoma are recognized as clinicopathologically distinct entities. Research into the cellular and molecular origins of these lymphomas is ongoing; variants and new entities are becoming evident. Histological and immunohistochemical features of the spleen following treatment for lymphoma are complex and may cause diagnostic confusion. Inflammatory and reactive processes in the spleen can also provide clinical, radiological or pathological mimicry of lymphomatous involvement.