Management of focally malignant pedunculated adenomatous colorectal polyps.

A hospital record review identified 59 patients whose sole colorectal pathology was a pedunculated, adenomatous polyp with a focus of malignancy confined to the head of the tumor. Thirty-one patients had polyps with in-situ carcinoma, and 28 patients had foci of invasive carcinoma. Sixteen patients who had lesions in situ underwent laparotomy, and not a single instance of metastasis was found. Twenty patients who had carcinoma in situ received only local treatment, and 15 are alive and well. None of the patients treated locally has developed subsequent colorectal cancer, and 12 have survived at least five years following treatment. Of the 28 patients who had invasive carcinoma confined to the head of an adenoma, 19 are alive and well, and 17 have lived five years or more following treatment. There was one instance of lymph-node metastasis, which occurred in a patient who had a malignant lesion extending to the neck of the tumor and tumor cells in the lymphatics in the head of the polyp. All of the eight patients treated locally are alive and well, and five have lived at least five years following treatment. The results of this study, coupled with the rarity of reported metastasis from focally malignant, pedunculated, adenomatous colorectal polyps, strongly suggest that local treatment is sufficient for the vast majority of these lesions. Evidence from the literature suggests that resective therapy should be considered when 1) lymphatics within the head of the polyp contain tumor cells; 2) the cancer is highly undifferentiated; 3) the pedicle is extremely short and malignant changes extend to the neck of the adenoma.