Figure 1.

Stage T1a signet ring cell carcinomas (SRCC) in CDH1 germline mutation carrier. (a) A 9 mm focus (the left two thirds of the frame) occupies the full thickness of the mucosa under an intact epithelium (hematoxylin–eosin stain, original magnification 40 ×). Inset frame shows signet ring cells in the lamina propria (original magnification 400 ×). Adapted from Charlton et al.^{( 9 )} (b) A SRCC showing typical SRCs in the luminal part (one SRC is marked with an arrow) and smaller, less‐differentiated cells at the base of the foci (box). Adapted from Humar et al.^{( 11 )}