Pocket Oncology (Pocket Notebook Series), 1st Ed.


Jean K. Lee and Leonard Saltz


Epidemiology and Classification

Appendiceal neoplasms are rare & usu. found incidentally; found in 1% of appendectomy specimens & comprise <1% of all intestinal neoplasms (∼0.12 cases/1000000)

Main histologic types:



Adenocarcinoids (goblet cell CAs)



Epithelial tumors: Adenoca more common 1° malignancies of appendix; 3 subtypes include:

Mucinous adenoca (most frequent)


Signet ring cell adenoca (least frequent, SEER database, NCI)

Appendiceal adenoca biologically resembles colonic adenoca; signet ring cell form w/poor prognosis

Mucinous appendiceal tumors range from low-grade benign mucinous cystadenomas to high-grade invasive malignancies cystadenomas can develop into mucoceles & recur as disseminated peritoneal mucinous tumors → pseudomyxoma peritonei, mucinous implants in the peritoneum characteristic “jelly belly”; mucinous tumors have predilection for peritoneal dissemination

Rare mucinous cystadenoca identified by invasion through appendiceal wall or epithelial cells in peritoneal mucus

Clinical Presentation, Staging, and Prognosis


Appendiceal adenoca often present as acute appendicitis

May also p/w abdominal pain, ascites, abdominal mass, & increasing abdominal girth

In adv cases peritoneal carcinomatosis & intestinal obstruction in pseudomyxoma peritonei

CT scan characteristics: Mucocele seen as well-defined mass usu. in the RLQ, adj to cecum; presence of intramural nodule suspicious for cystadenoca; characteristic peripheral location of tumor w/central displacement of small bowel in pseudomyxoma peritonei

Staging based on AJCC TMN staging for appendiceal CA

Prognosis: 5-y survival rates for appendiceal adenoca:

Stage I 81.1%

Stage II 52.6%

Stage III 32.9%

Stage IV 22.7% (SEER, 1973–2005)

Prognosis varies according to histologic type; mucinous & intestinal-type adenoca w/58% & 55% 5-y disease specific survival, respectively; signet ring cell CA w/worst prognosis (27%)


Epithelial tumors of appendix:

Appendectomy for simple mucoceles, cystadenomas, some cystadenoca; important that the tumor does not rupture intraoperatively

Right hemicolectomy indicated for cystadenoca w/mesenteric involvement, complicated mucoceles w/terminal ileum/cecum involvement, cystadenoca, goblet cell


Right hemicolectomy standard of care. Role of adjuvant chemotherapy unclear w/lack of prospective randomized trials. In general, adjuvant 5-FU-based chemotherapy recommended for pts w/node-positive intestinal type adenoca

Data extrapolated from studies for adjuvant chemotherapy for node-positive colon CA. In cases of intraperitoneal dissemination optimal tx unclear; surgical cytoreduction performed in selected pts

Benefit of systemic chemotherapy in adv met setting unclear due to lack of prospective trials. NCCN Guidelines do not exist for appendiceal adenoca & are currently based on systemic chemotherapy paradigms for CRC (5-FU & platinum drug; see Colon Cancer)

Pseudomyxoma peritonei: Recommend repeated surgical debulking for sx disease & is not curative; radical surgical cytoreduction of intra-abdominal & pelvic disease & more aggressive Rx w/IPHC used in some centers. However, this approach is not universally accepted as standard practice

Optimal tx of mucinous appendiceal adenoca unclear given lack of prospective studies; options include cytoreductive surgery, systemic chemotherapy, intraperitoneal chemotherapy including intraoperative HIPEC & EPIC