The tumour histopathology “glossary” for AI developers
Fig 4
Immunohistochemistry (IHC) and multiplexing.
(A) Singleplex IHC and tissue microarrays (TMAs). Left: Preserved nuclear expression of the mismatch repair protein MSH6 in a colorectal adenocarcinoma sample (asterisks). Arrow: Preserved expression in stromal fibroblasts. On the right, the principle of TMA construction: Tissue cores, usually 6 to 10 mm in diameter, are punched and transferred to a new FFPE block, which is composed of multiple patients and tissues. Inset: Overview of colorectal cancer tissue and illustrative punches. (B) Basic multiplex immunofluorescence (mIF) panel on colorectal mucosa consisting of 2 markers and DAPI (blue) as a standard nuclear stain. CD20 (light blue) labels B-cells and a lymphoid follicle (arrowheads). Beta-catenin stains colonic crypts (red, arrows). (C) Extended mIF panel with 6 markers and DAPI. Beta-catenin (red) highlights colorectal adenocarcinoma glands (asterisks), while the space between malignant glands is composed of immune cells, such as B-cells (CD20, light blue), and macrophages (CD68, green, black arrowheads). CD31 (orange) highlights blood vessels (grey arrowheads, intermixed with SMA, yellow) and might suggest vascular invasion. The stroma is represented by Vimentin (purple, grey arrowheads)-positive fibroblasts and smooth muscle (SMA, yellow. arrow). CD, Cluster of Differentiation; SMA, smooth muscle actin.