Ultramicroscopic Structure of the Rheumatoid Nodule

Abstract
The necrotic center of 6 rheumatoid nodules was examined histologically, histochemically and by electron microscopy. Collagen (mostly of the immature type) filamentous material (some electron dense and some less electron dense) cell debris, fat globules and intact cells with unbroken cell walls were identified. The dense filamentous material is identified with the fibrinoid of light microscopy.