Fig. 2
From: Iris metastasis preceding diagnosis of gastric signet ring cell adenocarcinoma: a case report
Representative photomicrograph showing tumor cells infiltrated onto the iris. H&E stain. PAS stain, and immunostaining. a: Hematoxylin and eosin (H&E) stain photomicrographs showing signet ring-like tumor cells and melanin containing-cells (arrowhead) in the interstitium of iris. b: Periodic acid-Schiff (PAS) stained section showing tumor cells containing a large amount of mucin. c: Immunostaining showing positivity for CK-CAM5.2. d:, e:, and f. Immunostaining showing negativity for CK7 and CK20, and positivity for CDX2 indicating enteric differentiation of the tumor cells, and primary tumor location might be gastrointestinal tract