[Hairy cell leukemia. Light and microscopic and electron microscopic examinations (author's transl)]

Two cases of a typical hairy cell leukemia are presented. The light microscopic findings within the bone marrow, lymph nodes and spleen are documented. The hairy configuration of tumor cells can best be seen in semithin sections of white cells of the peripheral blood. Electron microscopically, the organelle composition of hairy cells (including the characteristic ribosome lamellae complex) is demonstrated. The significance of morphological observations for the diagnosis of hairy cell leukemia and the differential diagnosis of this tumor disease are discussed. From the electron microscopic observations of intercellular cross-banded structures it seems possible that the increase of intercellular material demonstrable light microscopically by silver impregnation is the consequence of synthesis of collagen type IV. The conclusion is drawn from findings in our cases and from reports in the literature that hairy cell leukemia is a clinically and structurally defined syndrome rather than a pathological entity.