Intra-cytoplasmic crystalline inclusions in acute myeloid leukemia: a rare event

Unusual intracytoplasmic crystal-like inclusions within granulocytic precursor cells from a patient with acute myeloid leukemia (AML) are described. Based upon their cytochemical and immunochemical properties, the possible composition and origin of these inclusions are discussed. They represent a rare event in leukemic cell metabolism since, to our knowledge, only 1 case with identical characteristics has previously been reported.