Ultrastructural peroxidase pattern indicating cellular maturity in myelomonocytic leukaemia

The ultrastructural pattern of endogenous peroxidase of monocytes has been investigated in bone marrow samples as well as in the blood of patients labelled as myelomonocytic leukaemia (MML) after clinical and laboratory investigation. The predominance or the exclusive presence of a granular pattern in the bone marrow proved to be consistent with chronic MML cases. On the other hand, the presence of the peroxidase in RER, nuclear envelope, Golgi complex and granules in the bone marrow and even in the peripheral blood occurred in acute MML patients.