Functional and morphologic characteristics of the leukemic cells of a patient with acute monocytic leukemia: correlation with clinical features.

The clinical course of a patient with acute monocytic leukemia and prominent infiltration of the skin and testes is described. In vitro studies demonstrated that the circulating monocyte precursors were capable of adherence to nylon fibers, and phagocytosis of bacteria and latex particles. In vivo, migration of leukemic cells to skin windows was observed. Extreme nuclear folding, marked surface activity, and morphologic features suggesting nuclear and cytoplasmic maturation were seen by light and electron microscopy. The presence of morphologically and functionally more differentiated monocytic cells may account for the marked tiuuse invasion in this patient and, possibly, in other patients with monocytic leukemia.