Primary signet-ring carcinoma of the large bowel. Report of nine cases.

Nine cases of signet-ring carcinoma have been observed from among 800 consecutive histologic cases diagnosed as adenocarcinoma of the colon during a period of 10 years (0.9%). This group of nine patients (Group A) has been matched for sex, age, and stage with a group of 45 patients affected by ordinary carcinoma of the colon (Group B). Clinical and histologic parameters, including symptoms, primary tumor site, free interval from primary surgery, histochemical investigation of intracytoplasmic mucins, and survival, were evaluated. The results of this investigation showed no clinical differences between signet-ring carcinoma and ordinary carcinoma, and no statistically significant results were observed regarding the frequency of local recurrence and actuarial survival