Marrow Cell Uptake by Megakaryocytes in Routine Bone Marrow Smears during Blood Loss

Abstract
In studying smears of marrow aspirates, the presence of normal appearing hemopoietic cells within megakaryocytes was found. Routine marrow smears from 125 patients were searched. The presence of marrow cells (granulocytic, erythroid, and lymphoid cells) within megakaryocytes was seen in 16 cases of whom 9 had documented bleeding and 5 had carcinoma. Three patients were suspected of bleeding but this was not documented. Fifty-six percent of patients with bleeding and 83% of patients with carcinoma seen during this period displayed this phenomenon. A search for this phenomenon in routine marrow smears may reveal unsuspected blood loss.