Age, site and distribution of subepithelial neurosecretory cells in the appendix

Malignant neoplasms of the appendix

BACKGROUND

Appendiceal neoplasms, first described in 1882, are still rare, with pre-operative diagnosis invariably difficult. We present our 10-year experience of these lesions with a review of current epidemiology, pathology and treatment modalities.

MATERIALS AND METHODS

A retrospective histopathological review of all appendicectomy specimens was completed between April 1994 and December 2003 to identify patients diagnosed with malignant neoplasms. Patient demographics, operative details, histopathology and clinical outcomes were obtained from case notes. A literature search of the PubMed database was then performed using the medical search headings; appendix, tumour, neoplasm and malignancy.

RESULTS

Twenty-two patients (eight men) were identified during the study period, with no age difference between gender (mean age in women 58, range 14-83 vs mean age in men 55, range 16-78). Eleven patients were found to have carcinoid-type tumours, eight patients with adenocarcinomas and three patients with lymphomas. Other appendiceal pathologies were identified after appendicectomies, hemicolectomy and oophorectomy. Mean follow-up was 41 months (range 1-125 months). Fourteen patients were alive at the end of follow-up. Patients with classical carcinoid tumours (CCT) had better outcomes than patients with the goblet cell carcinoid, adenocarcinoma and lymphoma.

CONCLUSIONS

From our own experience and a subsequent review of the literature, we recommend right hemicolectomy as the treatment of choice for all malignant appendiceal neoplasms, except for small CCT less than 2 cm in diameter at the tip of the appendix, with a low proliferative index, without angiolymphatic or mesoappendiceal extension. Further adjuvant therapy should be considered after oncological assessment.

Surgical treatment of malignant carcinoid tumours of the appendix

Since their first description in 1882, malignant neoplasms of the appendix still remain rare. Malignant carcinoid tumours are the most common accounting for 85% of all appendiceal neoplasms. Preoperative diagnosis is invariably difficult, and precise treatment protocols for these neoplasms remain unclear. We reviewed our experience and searched published evidence to produce management guidelines. A retrospective review of all malignant carcinoid tumours diagnosed in our hospital between April 1994 and December 2003 was performed. Patient demographics, operative details, histological types and clinical outcomes were retrieved from case notes supplemented by a questionnaire to the patient's General Practitioner. A literature search was then performed. Nine patients were identified with classical carcinoid tumours (CCT); (M = 3 and F = 6, mean age: 43, range 14-81) and two patients with goblet-cell morphology (F = 2, age 46 and 76). Mean follow-up was 63 months (range 1-125 months). Nine patients were alive at the end of follow-up. Appendicectomy was performed for acute appendicitis. Other appendiceal pathologies were identified following hemicolectomy and oophorectomy. CCT are the most common tumours and have the better prognosis. From our experience and subsequent review of the literature, we recommend right hemicolectomy as the treatment of choice for malignant carcinoid tumours. However, small CCTs less than 2 cm in diameter at the tip of the appendix, with a low proliferative index, without angiolymphatic or mesoappendiceal extension can be treated by appendicectomy. Following oncological assessment, further adjuvant therapy should be considered for patients with advanced disease.

Neoplastic lesions of the appendix

Neoplasms occur in 0.5 per cent of appendices. Ultrasonography or computed tomography is beneficial, but preoperative detection is rare. At operation, the diagnosis is considered in under half of cases. Mucocele, localized pseudomyxoma peritonei, benign tumours and most appendiceal carcinoids are cured by appendicectomy alone. Right hemicolectomy is indicated for: (1) invasive adenocarcinoma; (2) tumours close to the caecum; (3) lesions larger than 2 cm; (4) mucin production; (5) invasion of the lymphatics, serosa or mesoappendix; and (6) cellular pleomorphism with a high mitotic rate. Tumours of 1-2 cm, small mucinous carcinoids, adenocarcinoma confined to the mucosa, and tumours in children may be treated by appendicectomy alone at the surgeon's discretion. The 5-year survival rate associated with classical carcinoid is more than 90 per cent. The prognosis of mucinous carcinoid is intermediate between that of classical carcinoid and well differentiated adenocarcinoma. The prognosis of adenocarcinoma is determined by Dukes' stage and is similar, stage for stage, to that of colorectal carcinoma.