Giant Mucocele of the Appendix

Abstract

Objective. Clinical and imaging (sonographic and computed tomographic [CT]) findings in 3 cases of giant mucocele of the appendix are described. Methods. Clinical records of 3 cases of giant mucocele of the appendix were reviewed. All patients had a basal B-mode sonographic examination and a contrast-enhanced sonographic examination using a second-generation low-mechanical index contrast medium. In all cases, a dual-phase spiral CT examination was carried out. Results. In 2 cases, the abdominal masses were discovered in asymptomatic patients; 1 patient had vague abdominal discomfort. A pathologic diagnosis of benign cystoadenoma was found at pathologic examination in all cases, and malignant pseudomyxoma peritonei was disclosed in 1 patient 1 year later. Common sonographic findings were as follows: (1) a huge abdominal mass with a maximum diameter ranging between 20 and 25 cm; (2) a thin hyperechoic border without either solid vegetations or signs of infiltration of surrounding tissues; (3) a complex internal echo structure with anechoic lacunae interspersed between curvilinear, wavy bands of echogenic material (the so-called sonographic onion skin sign); and (4) avascularity of the masses shown on contrast-enhanced sonography with a low-mechanical index medium. At CT, a well-circumscribed cysticlike mass of low attenuation was displayed in all cases. There was lack of enhancement during a dual-phase examination in 2 cases; in the other, a small peripheral area of faint enhancement was appreciated. Only in the latter case could CT reliably assess the origin of the mass. Conclusions. It is suggested that a combination of sonographic (namely the onion skin sign) and CT findings may aid in the correct preoperative diagnosis of giant mucocele of the appendix.

Double trouble: a rare presentation of mucocele of appendix

“…In cases of mucocele of the appendix, if the outer diameter of the appendix is 15 mm or more, is diagnostic with 83% sensitivity and 92% specificity. 12,13 Another sign is considered to be specific for diagnosis of mucocele of the appendix is onion skin appearance. 14 CT can be used to detect the signs specific to mucocele of appendix with high accuracy which includes presence of appendix lumen more than 1.3 cm, cystic dilatation, and wall calcifications.…”

Appendiceal mucocele—A rare case report

“…USG can be used to differentiate between mucocele and acute appendicitis. In case of acute appendicitis, the outer diameter threshold of the appendix is 6 mm, and 15 mm and more indicates the presence of a mucocele, with 83% sensitivity and 92% specificity [[12], [13], [14], [15]]. CT is regarded as the most accurate method of diagnostics.…”

Large Mucocele of the Appendix at Laparoscopy Presenting as an Adnexal Mass in a Postmenopausal Woman: A Case Report

“…Usually, CT is considered the most informative imaging technique although the diagnosis is more difficult when calcifications are absent and it can fail to identify the organ of origin, as demonstrated in the literature [3, 19, 20]. In the case of giant mucoceles, the diagnostic problem may be even more challenging because of the difficulties in defining the precise anatomic relationship with the cecal region and also for the fact that most CT findings are insensitive [21]. …”