Histo: Acute Appendicitis Flashcards
Identify the layers and other normal features.
Yellow star: Mucosa
Blue star: Submucosa
Black star: Muscularis propria/externa
Red star: Serosa
Red arrow: Lamina propria
Yellow arrow: Surface epithelium
Black arrow: Apidose tissue
Blue arrow: Artery
Green arrow: Lymphoid tissue
Identify yellow star
Yellow star = Lymphoid hyperplasia with germinal centers in the submucosa
Identify features
Identify timeframe
Identify what is happening
Black star: Neutrophils within a crypt in the mucosa
Yellow star and yellow arrow: Neutrophils within the lamina propria within the mucosa
Early Acute Appendicitis
Ultimately the action of lysosomal enzymes e.g. proteases, released by neutrophils as they die and secondary bacterial infection results in necrosis and ulceration of the mucosa.
Red star: Normal Mucosa
Yellow star: The mucosa is necrotic and ulcerated
Yellow arrows: Neutrophils between smooth muscle cells of muscularis propria. The inflammation has progressed outwards from the mucosa.
Black star: Fibrinopurulent exudate on serosa
Yellow star: Oedematous serosa with neutrophil infiltrate.
The inflammation has become transmural.
Identify Layers
Identify abnormal features (yellow star, yellow arrow)
Green star: Mucosa
Blue star: Submucosa
Black star: Muscularis Propria/extern
Red star: Serosa
Yellow star: The mucosa is focally necrotic and ulcerated (note that glands cannot be seen)
Yellow arrows: Focal fibrinous serosal exudate.
When extensive, the transmural inflammation can lead to transmural necrosis and thus gangrenous appendicitis which has a righ risk of rupturing.
Layers of the appendix
Black star: Fibrinous exudate on serosa
Yellow star: Oedematous serosa
Red star: Focal haemorrhage in submucosa
Blue star: Ulcerated mucosa with necrotic exudate.
MP: Muscularis Propria
