Fig. 19. A. Cross-section of a 27-week-gestation placenta. Delivery was due to intrauterine growth retardation and fetal distress. Massive perivillous fibrinoid is seen as perpendicular bands of white tissue separating nests of normal-appearing villous tissue. B. Microscopic appearance is quite distinct from an infarct. The villi are not infarcted, but they are avascular and there is loss of the syncytial trophoblast layer, which is replaced by firm eosinophilic material within which is proliferation of “X cells” (hematoxylin and eosin, ×10).