Rituximab-induced acute thrombocytopenia in patients with splenomegaly B Cell lymphoma: an underdiagnosed but severe complication.

Rituximab is popularly used in the treatment of B-cell lymphomas that bear CD20 antigen. Most of the adverse events (AEs) induced by rituximab are infusion-related symptoms. However, rituximab-induced acute thrombocytopenia (RIAT), which often develops within the 1-3 days after rituximab administration, is relatively unusual, severe, and usually self-recovering. Until now, most of the reports about RIAT were described as case reports and RIAT often occurred in patients with mantle cell lymphoma (MCL). Here, we report two patients who developed severe RIAT, one patient had a refractory and relapsed follicular lymphoma (FL), and the other patient was newly diagnosed with splenic marginal zone lymphoma (SMZL). RIAT is a rare, under-diagnosed but serious adverse event that should arouse attention to clinicians, and routine blood count monitoring should be considered after the administration of rituximab, especially for high-risk lymphoma patients or patient with splenomegaly.