During the introductionary cytophathology lecture by Flemming Fryd Johansen, he mentioned the following patterns of necrosis; coagulative, liquefactive, gangrenous, caseous, fibrinoid and fat necrosis. In my textbook “Patologisk Anatomi” they also list gummatous and hemoragic necrosis. Which list is correct and what is the basis for this difference between the textbooks? Is there any principle behind which types of necrosis obtain their own names?
The reason for the discrepancy is that you can subdivide necrosis by morphology or etiology. Morphological forms of necrosis are coagulative necrosis, liquefactive necrosis, fibrinoid necrosis (is probably a form of coagulative necrosis?), fat necrosis and caseous necrosis. Hemorrhagic necrosis is (usually) coagulative necrosis combined with bleeding into the necrotic area. Gummatous necrosis refers to spirocete infection as the cause (syphilis), whereas gangrenous necrosis is a clinical term.