FP7.3 - Acute Appendicitis and Lung Metastasis – A rare combination

Abstract Background Lung cancer is the third most common cancer in the UK. Although widespread metastasis is common, metastasis to the appendix is rare. Here we present a case of acute appendicitis secondary to lung metastasis. Case Presentation An 84-year-old man was admitted with a two-day history of right iliac fossa and suprapubic pain. He was known to have previous lung cancer treated with radical radiotherapy. Bloods on admission revealed elevated inflammatory markers with WCC 14.73 x 109/L and CRP 71.1mg/L. A Computed tomography was performed which showed acute appendicitis with perforation. An emergency laparoscopic appendicectomy was performed which showed a mid-appendiceal perforation with a localized abscess cavity. His recovery was uneventful, and the patient was discharged on postoperative day 2. Histological analysis revealed an adenocarcinoma in the appendicular lumen and within the muscle wall extending to the serosal surface. Immunochemistry profile was positive for CK, CK-19, TTF1 and Napsin A favoring a diagnosis of lung adenocarcinoma which was rationalized in the lung MDT. The patient remains under the respiratory physicians for close follow up. Discussion Lung metastasis to the appendix causing acute appendicitis is uncommon, with only twelve cases of appendiceal metastasis reported in the literature, ten of which presented with a perforated appendix. It may be considered as a differential for the cause of perforated acute appendicitis especially in patients with background of lung cancer.