Myeloid and Related Disorders

Abstract

Because of its microenvironment, the spleen will often have manifestations of bone marrow disease. Specifically, marrow-derived abnormalities of the myeloid series are apparent in the spleen. Proliferations of myeloid elements due to administration of cytokines, especially granulocyte colony-stimulating factor (G-CSF), are illustrated. This is an important mimic of other myeloid disorders in the spleen, including acute myeloid leukemia (AML). AML in the spleen is rare but can be seen both as a primary process and a transformation of chronic myeloid disorders. Splenic manifestations are most commonly seen in chronic myeloid disorders such as chronic myelogenous leukemia, primary myelofibrosis, polycythemia vera, and chronic myelomonocytic leukemia. Each of these has some unusual and occasionally characteristic findings in the spleen. Although more rare, myelodysplastic syndromes may also present with splenic pathology. Systemic mastocytosis often involves the spleen and the pathologic findings are illustrated. Histiocytic sarcoma, a rare and aggressive disorder, is illustrated. Both gross and histologic images are included. Where appropriate, immunohistochemical stains are also shown.