NCIt definition : Stage IIB includes: T4a, N0, M0, Any G. T4a: Tumor invades the visceral peritoneum,
including acellular mucin or mucinous epithelium involving the serosa of the appendix
or serosa of the mesoappendix. N0: No tumor involvement of regional lymph node(s).
M0: No distant metastasis. (AJCC 9th ed.);