[Signet ring cell adenocarcinoma of the colon (signet ring carcinoma): is it really a rare neoplasm?].

The Authors report two cases of primary carcinoma of the colon-rectum largely invasive, characterized signet ring cells. This is an uncommon neoplasm representing only 2% of primary carcinoma of the colon-rectum. The Authors discuss the diagnostic and therapeutic approach through a wide review of the literature.