Apparent discharge of cell fragments from blasts cells in acute leukemia. An ultrastructural study

In the blast cells of three patients who had leukemia, formation of small surface blebs and the apparent discharge of small cytoplasmic fragments were observed by light and electron microscopy. An ultrastructural study showed that they consisted of either double membrane-lined vacuoles or solid cytoplasmic fragments. The exact cause of this phenomenon is not known, but may be related to the complex alterations in the surfaces of malignant cells.