Clinical Manifestations and Outcomes of Lung Cancer Patients With Appendiceal Metastasis

ABSTRACT

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.