Ultrastructural morphology of leukemic cells from 14 dogs.

Transmission and/or scanning electron microscopic features of leukemic cells from seven dogs with myelomonocytic leukemia, four dogs with monocytic leukemia, and three dogs with lymphocytic leukemia were studied. Few ultrastructural features distinguished normal cells from leukemic cells. Nuclear to cytoplasmic asynchrony, abnormal cytoplasmic granules, nuclear pockets, and cytoplasmic fibrillar bundles were seen more frequently in leukemic cells. Small ridges or ruffles and a few microvilli were surface characteristics of cells from dogs with myelomonocytic leukemia. An occasional cell had large undulating ruffles. Cells from dogs with monocytic leukemia and lymphocytic leukemia usually had smoother surfaces.