“…Synchronous as well as metachronous adenomas are frequent with a high adenoma/carcinoma ratio that may suggest a slower adenomacarcinoma progression rate than in Lynch syndrome. 16,21,31,33,[35][36][37][38][39] Whereas colorectal cancers linked to Lynch syndrome are characterized by poorly differentiated tumors, mucinous differentiation, an expanding growth pattern, and abundant lymphocytic reactions (including tumor-infiltrating lymphocytes, peritumoral lymphocytes, and Crohn-like reactions), FCCTX tumors typically show a more 'sporadic-like' phenotype with medium high differentiation, glandular and infiltrative growth patterns, and frequent dirty necrosis ( Figure 2). 37,38 The lack of distinct histopathologic features makes identification of FCCTX-associated colorectal cancer challenging from a pathologist's perspective and underscores the importance of obtaining a family history of cancer.…”