Carcinoid tumors of the appendix. Prognostic factors and evaluation of indications for right hemicolectomy.

BACKGROUND/AIMS: Carcinoid tumors of the appendix are thought to be the most common type of appendiceal neoplasms. Although the vast majority of appendiceal carcinoids behave in a benign fashion, they are considered malignant because they all have the potential for invasion, metastasis and production of physiologically active substances. The aim of our study is to evaluate the gravity of the prognostic factors and the indications for extended surgical treatment.
METHODOLOGY: Twenty-four patients, six male (aged from 18 to 59 years) and eighteen female (aged from 16 to 27 years) are included in our study. All these patients were managed and followed-up in our section during the last 17 years (follow-up range 10-17 years). Following confirmation of the diagnosis, secretion of 5-HLAA (5-Hydroxy-Inndole-Acetic Acid) was measured after a 24-hour collection of urine. Moreover, ultrasound (US) examination of the liver and computerized tomography (CT) scanning of the upper abdomen were performed after the operation in all patients. Also, patients with tumor size more than 1cm underwent a Somatostatin Receptor Scintigraphy (Octreoscan). The follow-up data of all patients included measurement of 5-HLAA and US examination every six months.
RESULTS: The most common site for the tumors was the tip of the appendix (18/22). In the rest of the cases, the neoplasms were located in the base (4/22) and in the body (2/22), while in one patient the mesoappendix was invaded. In sixteen patients the tumor size was less than 1cm, in seven patients the tumor diameter was measured to be 1 to 2cm and in one patient the tumor was 3cm. Most of our patients (16/22) underwent only an appendicectomy, while in the rest of them (in the patients with tumor size between 1-2cm and in the patient with invasion of mesoappendix) a right hemicolectomy was performed. No patient was found to have metastatic disease during the operation, while the patient with invasion of the mesoappendix developed metastases in the lung, two years after the operation.
CONCLUSIONS: Carcinoid tumors of the appendix, in most cases, are found incidentally during appendicectomies, especially in young females and usually are less than 1cm in size, which is probably the reason of the absence of metastases in all cases. Histological examination and size of the tumor are important factors that contribute to the selection of the surgical treatment and both must be estimated by the surgeons to make the final choice.