Fig. 4: TLSs with and without a germinal centre in DCIS.

A Multispectral IF image of a DCIS duct with adjacent zone-TLS consisting of a CD20⁺ B-cell follicle surrounded by a CD3⁺ T-cell zone. Orange: CD20, green: CD3, red: CD8, white: keratinAE1/AE3, magenta: CD68, turquoise: FOXP3, and blue: DAPI. The scalebar represents 100 µm. B CD8⁺Ki67⁺ double-staining IHC of DCIS lesion with large GC-TLS containing a Ki-67-positive germinal centre. Yellow: Ki-67, purple: CD8. The scalebar represents 500 µm. C, D Combined beeswarm- and boxplots with zone-TLS (C) and GC-TLS density (D) in relation to outcome, ER status, HER2 status, periductal fibrosis, Ki67 and COX2 expression (Wilcoxon–Mann–Whitney test) and grade (Kruskal–Wallis test). Significant associations are indicated as: *P < 0.05, **P < 0.01 and ***P < 0.001. The central line in boxes represent the median value, boundaries of boxes represent the interquartile range (IQR), and ends of whiskers represent values at 1.5x IQR. ^aoutcome, 0 = controls and 1 = cases. ^bhistologic grade was based on nuclear grade. ^cperiductal fibrosis, 0 = periductal fibrosis absent, 1 = present. ^dER, 0 = negative, 1 = positive; ER was considered positive when ≥10% of the luminal epithelial cells showed nuclear staining of any intensity. ^eHER2, 0 = negative, 1 = positive. ^fKi67 expression in DCIS cells, 0 = <14%, 1 = ≥14%. ^gCOX-2, 0 = low expression in DCIS cells, 1 = high expression in DCIS cells.