Villous adenoma accounts for only 1% of adenomas arising from the large intestine. Malignant changes are more common for villous adenoma than for tubular and tubulovillous adenomas. However, preoperative diagnosis of villous adenoma is rare and treatment remains contentious.
A 77–year–old woman was referred to Kochi Medical School (KMS) Hospital for treatment of villous adenoma of the appendix. Preoperative abdominal computed tomography (CT) revealed that the tumor was 3 cm in diameter and accompanied by a cystic structure on the distal side. Strong accumulation of fluorodeoxyglucose (FDG) on FDG–positron emission tomography–CT and elevated serum carcinoembryonic antigen concentrations suggested malignant change. Consequently, laparoscopic ileocecal resection with regional lymph node dissection was performed. Pathologically, atypical cells with enlarged nucleus were arranged in the villous structure.
Until the minimum surgical intervention is proven safe, when malignant change is likely, surgical resection with lymph node dissection should be considered.