Management of malignant mucinous adenomas

Malignant polyps are defined as adenoma with cancerous tissue penetrating into or through the muscolaris mucosae in the submucosa, and endoscopic removal is the most common treatment for such polyps. In the presence of malignant mucinous adenoma, defined as a malignant adenoma in which a significant amount of mucus is present in the stroma, the therapeutic approach is controversial and authors have performed surgical resection in all cases. The purpose of the study was to demonstrate that malignant mucinous adenoma is not a condition suggesting by itself a bowel resection.

Ten patients with malignant mucinous adenoma were enrolled in the study: endoscopic treatment alone was performed in 4 cases, and polypectomy was followed by surgical resection in 6 cases.

At a median follow-up of 74.2 months no distant metastases had occurred in any of the patients treated with endoscopic polypectomy alone; during the follow-up, 1 patient had a local recurrence and surgical resection was performed. Only one case of residual disease was found at histology among the patients in which endoscopic polypectomy was followed by surgical resection. No complications occurred after endoscopic treatment in any case.

In the absence of unfavorable histologic parameters, malignant mucinous adenomas should be managed with the same criteria of other malignant adenomas, and endoscopic polypectomy is considered as a safe and effective treatment when radicality criteria are fulfilled.