Most common neoplasm of appendix Is -

Ans. is 'b' i.e., Adenocarcinoma o Recent editions of both Sabiston and Schwartz write that now Carcinoid tumor (i.e. Argentaffinoma) in not the most common tumor of the appendix. Mucinous adenocarcinoma is the most common tumor of the appendix.Read below:"Although it was previously believed that carcinoid tumors were the most common appendiceal neoplasms, analysis of the Surveillance, Epidemiology, and End Results (SEER) database indicates that mucinous tumors of the appendix are more common: ___ Sabiston"Data from the SEER program identified mucinous adenocarcinoma as the most frequent histologic diagnosis (38% of total reported cases), followed by adenocarcinoma (26%), carcinoid (17%), goblet cell carcinoma (15%), and signet-ring cell carcinoma (4%)" ___ SchwartzRemember these important points about Carcinoid tumor of appendixo Carcinoid tumours are neuroendocrine tumors arising in the argentaffin tissue (Kulchitsky cells of crypts of Lieberkuhn)o They frequently contain sustentacular cells that express S-100o These tumours can occur in any part of the appendix but most common site is distal third i.e. tip of appendixo Unlike carcinoid tumours arising in other parts of the GI.T., it rarely gives rise to metastasis.