Giant lysosome like structures in promyelocytic leukemia. Ultrastructural and cytochemical observations

Electron microscopic and cytochemical studies were performed on the promyelocytes of a patient with acute promyelocytic leukemia and disseminated intravascular coagulation. Light and electron microscopic examination of the promyelocytes revealed the presence of both giant granules and Auer bodies. The promyelocytic giant granules and the Auer bodies exhibited cytochemical reactions, indicating the lysosomal nature of both. A common origin of these abnormal lysosomal structures and their possible relation to the coagulation disturbance is considered.