Sea Blue Histiocytosis Concordant With Immune Thrombocytopenic Purpura.

Sea blue histiocytosis is an unusual bone marrow finding in many haematological conditions or lipid metabolic diseases that by itself may not carry any prognostic value. It may occur rarely as a primary genetic clinical syndrome characterized by splenomegaly, hypertriglyceridemia and thrombocytopenia. More commonly, the presence of these lipid-laden blue-stained macrophages indicates an underlying condition characterized by increased bone marrow precursor cell turnover due to myeloproliferative conditions or ineffective erythropoiesis. Rarely may they be observed in cases of immune thrombocytopenic purpura (ITP) incidentally due to rapid megakaryocytic turnover. Sea blue histiocytosis should prompt the clinician to evaluate the patient for more sinister conditions such as myelodysplastic syndrome or infiltrative disorders.