The frequency in which CDH1 mutations are reported in lobular lesions in the literature is highly variable (42–82%, [12,13,14,15,37], and is highest in microdissected lobular in situ carcinoma lesions, 81–94% [38,39,40]), suggesting that mutation reporting is likely impacted by (i) the tumour cellularity of the individual specimens analysed, for what is described as a diffusely infiltrating tumour type; and (ii) the quality and sensitivity of sequencing technology used (panel, exome, whole genome). This evidence concerns the gene CDH1 and neoplasm.