Stage IV Appendix Neuroendocrine Tumor AJCC v8

**Semantic type:** Neoplastic Process

**Definition:** Stage IV includes: (T1, N0, N1, M1); (T2, N0, N1, M1); (T3, N0, N1, M1); (T4, N0, N1, M1). T1: Tumor measuring 2 cm or less in greatest dimension. T2: Tumor measuring more than 2 cm but less than or equal to 4 cm. T3: Tumor measuring more than 4 cm or with subserosal invasion or involvement of the mesoappendix. T4: Tumor perforating the peritoneum or directly invading other adjacent organs or structures (excluding direct mural extension to adjacent subserosa of adjacent bowel), e.g., abdominal wall and skeletal muscle. N0: No regional lymph node metastasis. N1: Regional lymph node metastasis. M1: Distant metastasis. (AJCC 8th ed.)

**Synonyms:** - Stage IV Appendix Neuroendocrine Tumor