Clinical Manifestations and Outcomes of Lung Cancer Patients With Appendiceal Metastasis

Metastatic involvement of the appendix from a primary distant tumor is uncommon, and the same holds true for tumors originating in the lungs. Consequently, data on pathogenesis, diagnostic approaches, therapeutic strategies, and outcomes of lung-to-appendix metastasis remain scarce. Here we describe two patients managed at our institution between September 2018 and August 2025 and integrate their data with 30 cases identified through a structured literature search, yielding an analytical cohort of 32 individuals. The cohort comprised 26 males and 6 females, with a median age at detection of appendiceal involvement of 63.5 years (range, 41-85 years). The median interval from primary lung-cancer diagnosis was 12 months (range, 1-54 months). Histotypes were small-cell carcinoma (n = 15), adenocarcinoma (n = 14), squamous-cell carcinoma (n = 1) and not otherwise specified (n = 2). At the time of appendiceal disease, 20 patients (62.5%) already harbored concurrent extra-appendiceal metastases. Surgical intervention was undertaken in 31 cases; appendectomy-performed open or laparoscopically-was the procedure of choice in 26 (83.9%). In summary, the appendix may serve as an unusual but clinically relevant sanctuary site in patients with advanced lung cancer, particularly those with small-cell or adenocarcinomatous histology. Systematic staging, tailored surgical resection, and individualized systemic therapy are essential to prolong survival and preserve quality of life.