Hemophagocytic Subtype of Intravascular Large B-cell Lymphoma: An Unusual Finding

Intravascular lymphoma (IVL) is an aggressive and rare disease with a poor prognosis classified by the World Health Organization (WHO) as a subtype of diffuse large B-cell lymphoma (DLBCL). It is characterized by a proliferation of large neoplastic B cells within the lumina of small blood vessels, with minimal or no infiltration of the surrounding extravascular tissue. The hemophagocytic subtype typically occurs in adults, with a median age of around 70 years and with no sex predilection. Herein, we present a case with hemophagocytic syndrome, including splenomegaly, fever, cytopenia (anemia and thrombocytopenia), macrophage activation syndrome and lymphocytosis observed on peripheral blood smear, which developed for seven weeks in a 75-year-old lady. Histological study and immunohistochemical staining of the bone marrow biopsy revealed a proliferation of atypical lymphomatous cells within the lumen of small blood vessels.