Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + • Most diagnosed during appendectomy for acute appendicitis• Some discovered as incidental findings during other abdominal procedures• Mucin secretion from peritoneal cystadenocarcinoma implants is the cause of pseudomyxoma peritonei +++ Epidemiology + • 4.6% incidence of benign tumors in appendectomy specimens• 1.4% incidence of malignant tumors in appendectomy specimens• Benign lesions include small carcinoid and mucocele• Malignant tumors include carcinoid, mucinous cystadenocarcinoma, and adenocarcinoma• Appendix most common location of GI carcinoids• Most carcinoids are < 2 cm and are located at the tip of the appendix• Carcinoids > 1.5 cm may exhibit malignant behavior• Widespread metastases are present in 10-50% of patients with appendiceal adenocarcinoma +++ Symptoms and Signs + • Diagnosis virtually never made preoperatively• Clinical presentation in most patients is either acute appendicitis or lack of symptoms• Clinical presentation in small portion of patients is the carcinoid syndrome or evidence of widespread metastases• Rarely is a palpable mass present• Ascites may be present in patients with a ruptured or metastatic mucin-secreting tumor +++ Laboratory Findings + • Findings consistent with acute appendicitis• Patients with carcinoid syndrome may have elevations of 5-hydroxyindoleacetic acid (HIAA) +++ Imaging Findings + • Most common radiographic findings are those consistent with acute appendicitis (enlarged appendix with peri-appendiceal fat stranding on CT)• Up to 15% of patients have formed peri-appendiceal abscesses• Tumors > 1-2 cm may be detected as an appendiceal mass on CT scan, although tumors usually obscured by surrounding bowel + • Acute appendicitis• Appendiceal abscess• Carcinoid• Mucinous cystadenoma• Mucinous cystadenocarcinoma• Adenocarcinoma• Adenocarcinoid• Lymphoma• Metastasis to the appendix +++ Rule Out + • Synchronous carcinoid neoplasms• Metastatic disease + • Most diagnoses depend on pathologic evaluation of the appendiceal specimen• Abdominal/pelvic CT scan to evaluate for metastatic disease• Somatostatin receptor scintigraphy can be helpful with carcinoid tumors• Up to 35% of patients with adenocarcinoma have a second GI malignancy +++ When to Refer + • Patients with evidence of lymph node involvement or metastatic disease + • Following recovery from initial surgical procedure, further resection should be considered +++ Surgery +++ Indications + • Carcinoids < 2 cm are treated with appendectomy alone• Carcinoids > 2 cm or with mucinous elements, or invasion of the mesoappendix or cecum, should have right hemicolectomy• All (nonmetastatic) adenocarcinoma should be treated with right hemicolectomy• Localized hepatic masses should be resected• Debulking of cystadenocarcinoma mucin-secreting peritoneal implants provides symptomatic relief +++ Contraindications + • Unresectable metastatic disease +++ Prognosis + • Very good for benign lesions and small carcinoids• Adenocarcinoma 5-year survival ... Your Access profile is currently affiliated with [InstitutionA] and is in the process of switching affiliations to [InstitutionB]. Please select how you would like to proceed. Keep the current affiliation with [InstitutionA] and continue with the Access profile sign in process Switch affiliation to [InstitutionB] and continue with the Access profile sign in process Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Error: Incorrect UserName or Password Username Error: Please enter User Name Password Error: Please enter Password Sign in Forgot Password? Forgot Username? Download the Access App: iOS | Android Sign in via OpenAthens Sign in via Shibboleth You already have access! Please proceed to your institution's subscription. Create a free profile for additional features.