Abstract
An 81-year-old woman was admitted to our hospital after three days of persistent right lower abdominal pain. Computed tomography scans showed a fecalith in the appendicular root and a periappendiceal mass of 32 mm in diameter. Based on the diagnoses of localized peritonitis and intra-abdominal abscess due to acute appendicitis, antibiotic therapy was initiated. Conservative therapy resulted in shrinkage of the abscess, and we performed laparoscopic interval appendectomy. Intraoperative findings revealed a severe adhesion between the appendix and right ovary, but there was no malignancy in the peritoneal cavity. Postoperative histopathological examination of the resected specimen demonstrated adenocarcinoma, mainly located in the subserosal layer of the appendix. Immunohistochemical staining revealed cancer cells derived from ovarian cancer. Therefore, we diagnosed metastatic appendiceal cancer. In cases of aged patients with acute appendicitis, it is important to differentiate the lesion and consider a possible diagnosis of appendiceal metastasis.
