The Necrobiotic Nodules of Rheumatoid Arthritis

Much has been written about the nodules of rheumatoid arthritis, which, though present in less than a quarter of the patients, ma) nevertheless be regarded as constituting an important, if not the most important, feature from the pathological point of view. Collins (1937) and others, including Parkes Weber (1943, 1944), Kersley and others (1946) have shown that the characteristic subcutaneous nodules consist of ioci of fibrinoid degeneration and necrosis, surrounded by a border of tissue reaction, notably by a palisade-like radiate arrangement of fibroblasts. Somewhat similar microscopic appearances have been described in pathological conditions of a different nature (granuloma annulare, necrobiosis lipoidica), but even if the histological features of the nodules of rheumatoid arthritis were absolutely pathognomonic, one would still be far from the discovery of the essential pathogenic agent. Allison and Ghormley (1931) made a great point of what they called " focal collections of lymphocytes'" in the synovial membrane of joints being almost pathognomonic of " proliferative arthritis of uncertain origin "-that is to say. of rheumatoid arthritis. But if one looks at their illustrations (for instance, p. 147, fig. 4; p. 169, fig. 3; and Plate VIII) one recognizes the presence (in these " focal collections ") of so-called " germ-centres " of Flemming. Now, surely such lymphadenoid foci with typical " germ-centres " can hardly be .considered as pathognomonic of any special disease. Apart from their conspicuous presence in normal lymphadenoid tissue (lymph glands, tonsils, the walls of the vermiform appendix and intestines, the Malpighian corpuscles of the spleen), they form a special feature in so-called lymphadenoid goitres, and are also not rarely found in thyroids from patients with Graves' disease. One of us (Parkes