In literature KD has been reported in association with systemic lupus erythematosis (SLE), Epstein Bar virus (EBV),
hemophagocytosis with a common presentation of fever and lymphadenopathy.2-4 The pathogenesis of Kikuchi disease in unclear but histological changes suggests immune response with presence of T cells and exposure to infectious agents with histiocytes.
PIDs can also occur with autoimmunity, autoinflammatory or
hemophagocytosis syndromes (3).
In addition, activated macrophages are sometimes noted to phagocytose erythrocytes, hence the term
hemophagocytosis (13).
Significantly increased histiocytes (Figure 1b, highlighted by CD68 immunohistochemistry stain, brown color, arrows) with
hemophagocytosis, macrophages engulfing lymphocytes, and cell debris in the cytoplasm (Figure 1c, Liu stain, arrow) were demonstrated.
The etiology of secondary HLH includes infection (especially Epstein-Barr virus infection), autoimmune diseases, and malignancies.[5] The pathological features of HLH are mononuclear macrophages and tissue cells from the bone marrow, spleen, liver, or lymph nodes phagocytose hemocytes which form a phenomenon of
hemophagocytosis. A trail guideline in 2004 suggested that treatment can be divided into initial and maintenance periods for the first 8 weeks based on dexamethasone, etoposide, and cyclosporine, and then intrathecal injection can also be given.
(2)
Hemophagocytosis or emperipolesis by neoplastic cells can be present.
Hemophagocytosis is the engulfment of hematopoietic cells by activated macrophages in tissue specimens.
Pancytopenia resulting from
hemophagocytosis in malaria.
A bone marrow biopsy demonstrated a hypercellular bone marrow with reactive changes and increased histiocytes with
hemophagocytosis. The patient met diagnostic criteria for HLH, including fever, splenomegaly, cytopenia, hypertriglyceridemia, hypofibrinogenemia,
hemophagocytosis in bone marrow, and elevated ferritin.
Although macrophage
hemophagocytosis is often seen on bone marrow examination, in the initial stages of the syndrome this finding may be absent (4,5).
Secondary
hemophagocytosis was also considered in the differential diagnosis because increased ferritin level was found in association with fever, pancytopenia, and splenomegaly.
The next common cause in this study was found to be dengue fever (21.7%) which may be due again to hypersplenism,
hemophagocytosis, or immune hemolysis.
