Clinicopathological features of signet-ring cell carcinoma of the colon and rectum: a case-matched study.

Primary colorectal signet-ring cell carcinoma (SRC) is a rare type of mucin-containing adenocarcinoma and little information exists about its clinicopathological features.The clinicopathological features of 27 patients with primary colorectal SRC were compared with non-signet-ring cell mucinous carcinoma (MC) and non-mucinous adenocarcinoma (NMC). To analyze survival and recurrence, we used matched control groups.The mean age of patients in SRC was significantly younger than that of NMC (p = 0.003). The ratio of metastatic lymph nodes to harvested lymph nodes was also significantly higher in SRC (48.5 +/- 30.6) than in either MC (29.8 +/- 26.3; p = 0.009) or NMC (22.0 +/- 21.6; p = 0.003). In stage II and III, SRC was found to be associated with a worse cancer-specific survival and a higher systemic recurrence rates than either NMC or MC.Primary colorectal SRC has distinctive clinicopathological features and is associated with a poorer prognosis than the other histological subtypes.