Adenovirus in the Intestinal Epithelium of a Foal with Prolonged Diarrhea

Histologically, there is diffuse marrow fibrosis and no neoplastic proliferation of megakaryocytes. Megakaryocytic myelosis has been considered in man as a variant of acute myelogenous leukemia with particularly prominent proliferation of megakaryocytes [ 11. Neoplastic megakaryocytes may be seen in peripheral blood smears 121, however, it has been thought that these neoplastic megakaryocytes usually do not appear in the peripheral blood [3]. In this case it was not possible to examine a blood smear, but the presence of numerous megakaryocytes in the sinusoids of liver and in the pulmonary capillaries indicates that they were probably in the circulation. Absence of significant petechial or diffuse hemorrhage in this case could not be explained satisfactorily.