Fig. 5From: Grade 3 well-differentiated neuroendocrine tumor of the rectum: a case reportHistopathologic findings. a Chromatin is increased in the atypical cells, which feature mitotic figures. Invasion involves the subserosa. Hematoxylin-eosin staining (magnification × 20). b MIB-1 index > 20%. c Positive staining for chromogranin A. d Positive staining for synaptophysin. e Positive staining for CD56Back to article page