You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Antischkow cells are seen in - and explain in detail?
Aschoff body (Fig. 15.13): It is spheroidal or fusiform characteristic lesion seen in rheumatic disease. Site: During acute RF, may be found in any of the three layers, in the perivascular interstitial region of the hea. Formation of Aschoff body consists of 3 phases: Early/exudative phase: It consists of a perivascular focus of swollen eosinophilic collagen surrounded by lymphocytes, plasma cells, and macrophages. Intermediate/granulomatous phase: It is pathognomonic of rheumatic myocarditis. It is a granulomatous lesion, with a central fibrinoid focus associated with lymphocytes (primarily T-cells), macrophages, Anitschkow cells (pathognomonic for RF) and occasional plasma cells. Anitschkow cells are plump activated macrophages, which have abundant cytoplasm. They have round-to-ovoid nuclei in which the chromatin is disposed of in a central, slender, wavy ribbon. These nuclei resemble a caterpillar when cut longitudinally (hence known as "caterpillar cells"). On cross section, these nuclei have an owl-eye appearance. Few Anitschkow cells may become multinucleated (with 2 to 4 nuclei) in which case, they are termed Aschoff giant cells. Late/healed /final phase: Aschoff body is replaced by a nodule of scar tissue.