BIOM20001 Lecture Notes - Lecture 65: Sarcoidosis, Necrosis, Neoplasm
Document Summary
Giant cells (fusion of macrophages under influence of ifn-gamma) Macrophages and fibroblasts attempt to wall off infection. Rim of fibroblasts and connective tissue if going on for long enough. Central zone of necrosis (cid:858)walls off(cid:858) offe(cid:374)di(cid:374)g age(cid:374)t defense mechanism. Could have a central zone of necrosis (caseating or non-caseating) Stimulated by talc, suture, silica, breast prostheses, vascular grafts. Too large to be phagocytosed and do not elicit inflammatory or specific immune response. Below is a giant cell attempting to engulf foreign material. Caused by macrophages releasing ros (cid:894)(cid:862)caseous(cid:863) = (cid:862)(cid:272)heesey(cid:863)(cid:895) Surrounded by a spherical mass of cells: epithelioid macrophages, lymphocytes, giant cells. Pink regions with no blue dots is caseous necrosis. Necrosis caused by macrophages secreting killer chemicals (ros etc. ). If the macrophages digest blood vessels you could cough up blood. Non-caseating granulomata in many tissues and organs e. g. lungs, lymph nodes, spleen, bone marrow, skin, liver. Collection of epithelioid macrophages, giant cells, rimmed by t-cells, fibroblasts.
