Endoscopically unobservable appendiceal adenoma treated using laparoscopically assisted surgery

Primary benign adenomas of the appendix occur rarely. According to appendectomy and autopsy reports, benign adenomas of the appendix are sporadically reported, accounting for ~0.02-0.08% cases.

We report the case of a 58-year-old woman with a segmental polyp protruding into the appendiceal orifice. The polyp was spotted during lower gastrointestinal endoscopy; however, treatment was postponed at the patient's request. During a confirmatory lower gastrointestinal endoscopy for treatment, the polyp was no longer found protruding from the appendiceal orifice and had disappeared. An appendicectomy was performed for diagnostic and therapeutic purposes. Pathological examination showed a low-degree atypical tubular adenoma with no malignant findings.

Despite the risk of perforation, surgical resection remains the gold standard for treating appendiceal adenoma. Resection can be performed endoscopically if the stem and base of the adenoma can be identified. In the present case, laparoscopy was a good indication from the safety standpoint, and it was radically curative. Furthermore, upon performing an appendectomy, the patient was informed of the risks of cancer-related complications or the need for additional resection.

This suggestive case proves that appendiceal tumors can disappear endoscopically depending on the timing of examination and treatment.