Rieder Cells

RIEDER CELLS (Rieder), pathological blood cells described by Rieder with irregular, sharply polymorphic nuclei. Observing them in acute leukemia, Rieder considered these cells pathological lymphocytes. This view is held at the present time by Naegeli, who ascribes to Rieder cells only a lymphatic origin. Pappenheim, however, considers R. c. pathological varieties of cells of lymphoid or myeloid origin with a particular feature in the structure (more correctly in the outline) of the nucleus. The nuclei of R. c. have the most diverse forms—lobed, various figures, sometimes with processes, or bizarre rosettes. Such polymorphism of the nucleus is associated by authors with irregular amitotic division and premature maturation of the cell (maturatio praecox), caused by the stormy process of blood formation. Sternberg considers R. c. cells of neoplastic (sarcomatous) nature, since he observed them in large numbers in cases of the leukosarcomatosis described by him. This view of the essence of R. c. is contradicted by the data of Ferrata, Tormini and other authors who observed R. c., besides in leukemias, in severe septic infections, in pernicious anemia, and in experiment in lead or phosphorus poisoning. The majority of authors at the present time hold the above-mentioned view of Pappenheim. The most characteristic R. c. are considered for leukemias, mainly acute; in other cases they are rarely observed.