We report a splenoma associated with an important megakaryocyte sequestration in peliotic sinuses. The diagnosis was done on surgical specimen of splenectomy performed for a painful splenomegaly occurring in a 71-year-old man presenting a primary idiopathic myelofibrosis. Histopathological features of these splenic microvascularization disorders, mainly occurring during hemopathy involving the spleen, are discussed. This case seems to confirm the hypothesis that splenoma could be an acquired splenic disease.