Lung cancer presenting as an acute appendicitis

Appendiceal metastasis is a rare complication of primary lung cancer and an extremely rare cause of appendicitis. We present the case of a 62-year-old male who presented with right lower quadrant abdominal pain which revealed not only appendiceal inflammation, but also a lung mass and mediastinal lymph nodes. He then proceeded to appendicectomy and two days post-operatively an endobronchial ultrasound-guided biopsy. His mediastinal lymph node biopsy revealed a lung adenocarcinoma and his subsequent appendiceal immunohistochemistry revealed the same staining pattern for thyroid transcription factor 1 (TTF-1) and cytokeratin 7 (CK-7). We conducted a literature review which revealed 12 previous case reports of lung metastasis to the appendix causing appendicitis including three patients in whom appendicitis was the presenting complaint leading to lung cancer diagnosis. This case highlights the diversity of presentations for patients suffering from metastatic lung cancer.