By comparing the mutation signatures of tubular adenomas, villous adenomas and FAP-CRC, we found that adenomas exhibited lower mutational rates than FAP-CRC and recurrent alterations were observed in well-known chromosomal instability (CIN) genes (APC, RAS, SMAD4 and TP53) and DNA damage repair genes (SUZ12, KMT2C, BCLAF1, RUNX1, and ARID1B) in the adenomas, suggesting the presence of genomic instability. This evidence concerns the gene SMAD4 and colorectal carcinoma.