Nuclear Bleb Formation in Human Bone Marrow Cells during Cytosine Arabinoside Therapy

Abstract

ABNORMAL nuclear blebs have recently been reported in the bone marrow cells of patients undergoing 5-fluoro-uracil treatment for neoplastic disease¹. Ultrastructural examination of these blebs revealed that they enclose areas of cytoplasmic material within their bulging projection and are unlike the nuclear invaginations described in some malignant cells² or the projections of nuclear material reported in certain chromosome abnormalities³. Investigation in our laboratory of the bone marrow of patients undergoing treatment with cytosine arabinoside revealed identical nuclear blebs containing cytoplasmic material in immature granulocytes. The condition was first noted in bone marrow samples 45 h after a single intravenous administration of the agent, 1,200 and 1,500 mg/m² body surface.