Digitally reinforced hematoxylin-eosin polarization technique in diagnosis of rectal amyloidosis

Figure 4 False negative case with extensive refraction and tiny deposits in digitally reinforced polarization view. A: No arresting positivity was observed in initial evaluation. Note the black-appearing area in the center of the circle [hematoxylin-eosin (HE), under polarization, 10×]; B: High-power digitally reinforced polarization view of the area in circle in panel A. The yellowish green birefringence in a small vessel (arrow) is distinguished after careful examination in comparison with the Congo-red image (HE, under polarization, 40×); C: Congo-red stain positivity in the same vessel (arrow) (bright field, 40×); D: Apple green birefringence of Congo-red polarization of the same vessel (arrow) (under polarization, 40×).