Aschoff body
Aschoff body | |
---|---|
Aschoff bodies are microscopic structures seen in patient with rheumatic fever | |
Differential diagnosis | rheumatic fever |
In
Appearance
Microscopically, Aschoff bodies are areas of inflammation of the connective tissue of the heart, or focal interstitial inflammation. Fully developed Aschoff bodies are granulomatous structures consisting of fibrinoid change, lymphocytic infiltration, occasional plasma cells, and characteristically abnormal macrophages surrounding necrotic centres. Some of these macrophages may fuse to form multinucleated giant cells. Others may become Anitschkow cells or "caterpillar cells," so named because of the appearance of their chromatin.
They are pathognomic foci of fibrinoid necrosis found in many sites, most often the myocardium. Initially they are surrounded by lymphocytes, macrophages, and a few plasma cells, but they are slowly replaced by a fibrous scar. Aschoff bodies are found in all the three layers of the heart, least chance in the pericardium.
Presence in cardiac lesions
The
Detailed description
The Aschoff nodules are foci of T lymphocytes, occasional plasma cells, and activated macrophages (Anitschkow cells) pathognomonic of rheumatic fever. These macrophages have abundant cytoplasm and central round nuclei in which chromatin condenses into a central, slender, wavy ribbon, the reason why they are sometimes called "caterpillar cells". They are especially found in the vicinity of small blood vessels in the myocardium and endocardium and occasionally in the pericardium, and also the
Evolution of nodules
Evolution of Aschoff nodules typically involve 3 stages of development all of which may be present in the heart at the same time of inspection.
Stage 1. Early
Stage 2. Intermediate proliferative /
Stage 3. Late fibrosis stage. It is the stage of healing by which the fibrosis of the Aschoff nodules occur in 12 to 16 weeks after the illness. The nodule becomes oval or fusiform in shape about 200 micrometer x 600 micrometer in width and length. With passage of months and years the Aschoff nodules becomes less cellular and collagenous tissue is increased. Eventually it is replaced by a small fibrocollagenous scar with little cellularity frequently located perivascularly.
History
The Aschoff bodies were discovered independently by the German pathologist Ludwig Aschoff 1904[1][2] and one year later by Paul Rudolf Geipel.[3]
References
- Who Named It?
- ^ K. A. L. Aschoff. Zur Myocarditisfrage. Verhandlungen der deutschen pathologischen Gesellschaft, Stuttgart, 1904, 8: 46-53. Translated in Willius & Keys, Cardiac Classics, 1941, pp. 733-739.
- ^ Geipel P (1905). "Studies on rheumatic myocardis". Deutsch Arch. Klin. Med. (in German). 85: 75.