Appendix cancer surgery

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Soroush Seifirad, M.D.[2]

Surgery is the mainstay of treatment for appendix cancer. The feasibility as well as determining the appropriate plan of surgery depends on the stage of appendix cancer at diagnosis. Tumor size plays the crucial role in determining the need for further surgery.

• Surgery is the mainstay of treatment for appendix cancer.

• The feasibility as well as determining the appropriate plan of surgery depends on the stage of appendix cancer at diagnosis.^[1]
• Carcinoid tumor are generally treated with appendectomy, right hemicolectomy and surrounding lymph nodes dissection.^[2]
• Non-carcinoid tumors are candied for tumor debulking surgery; in addition to right hemicolectomy and tumor dissection (also called cytoreductive surgery), gallbladder, as well ovaries and uterus in female patients might be excised. Tumor debulking surgery might accompanied by hyperthermic intraperitoneal chemotherapy (HIPEC), specially in high stage cases with peritoneal seeding as well as in patients with pseudomyxoma peritonei.^[1]
• Approach to appendiceal carcinoid tumor

• Tumor size plays the critical role in surgical planning for the patients with appendix carcinoid tumor.^[2]
• Patients with tumors larger than 2 cm should undergo right hemicolectomy.^[2]
• It has been controversial weather patients with smaller tumors benefit from right hemicolectomy or not? Although the Mayo Clinic study on 120 patients suggested appendectomy as the sufficient intervention in tumors smaller than 2 cm, but recent studies raised some concerns in this regard; indeed a higher potential for metastatic disease and lymph node metastasis has been demonstrated in new reports as well as SEER database, specially in mesoappendical invasion.^[3][4][5]

• European Neuroendocrine Tumor Society (ENETS) and North American Neuroendocrine Tumor Society (NANETS) consensus based guideline suggests right hemicolectomy for tumors between 1 and 2 cm in the presence of deep mesoappendiceal invasion, positive or uncertain margins, high proliferation rate, angioinvasion and mixed histology (adenocarcionid, goblet cell cacionid).^[6][7]
• For tumors smaller than 1 cm, simple appendectomy is adequate.

• Approach to mucinous adenocarcinoma of the appendix^[1]
• General expert consensus is in favor of right hemicolectomy within three months of initial appandectomy, the following aproach is recommended by Kelly et. al:

• First determine weather the tumor is ruptured or not?<math>\blacktriangledown</math>

• If not ruptured determine the grade <math>\blacktriangledown</math>

• Right hemicolectomy with lymph node dissection is the appropriate approach for high grade tumors
• In low grade tumors appendectomy would be enough

• If the tumor is ruptured <math>\blacktriangledown</math>

• In gross peritoneal disease imaging to evaluate eligibility for complete cytoreduction is warranted, and if it was feasable cytoreduction and HIPEC is recommended.^[8]
• In microscopic rupture the tumor grade plays the determinant role:<math>\blacktriangledown</math>

• laporoscopic evaluation and resection of the residual tumor is recommended for low grade tumors.
• High grade tumors should be treated with laparotomy, residual tumor removal, right hemicolectomy, omentectomy, right lower quadrant peritonectomy, plus bilateral oophorectomy in female patients, followed by HIPEC.

• Surgical approach to appendix mucocele

• Even if they appear benign in imaging studies, appendiceal mucoceles are candid of surgical resection.^[9][10]
• Careful resection and handling during surgery is warranted, since even a benign ruptured mucocele might result in peritoneal disease.
• Standard appendectomy with appendiceal mesentery resection is adequate in limited mucocele or even cystadenocarcinoma.^[10]
• Involvement of terminal ileum or cecum warrants a right hemicolectomy.^[9][10]

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