Appendiceal mucocele: A diagnostic dilemma in differentiating malignant from benign lesions with CT.
OBJECTIVE
The purpose of this study was to assess the feasibility of using CT to differentiate malignant from benign lesions in patients with pathologically confirmed appendiceal mucoceles.


METHODS
CT scans of 18 consecutively registered patients (11 men, seven women; age range, 21-78 years) with pathologically confirmed appendiceal mucocele were reviewed retrospectively. Patients were classified into three groups according to pathologic results: nonneoplastic mucocele (n = 3), mucinous cystadenoma (n = 10), and mucinous cystadenocarcinoma (n = 5). The nonneoplastic and mucinous cystadenoma groups were formed into a benign group, and the mucinous cystadenocarcinoma constituted the malignant group. Two experienced radiologists working in consensus assessed the shape, short diameter, density, contour, and wall thickness of the masses. The presence of calcifications, internal septations, soft-tissue thickening, periappendiceal fat stranding, intraperitoneal free fluid and pseudomyxoma peritonei were also evaluated. The CT results were compared for malignant and benign appendiceal mucoceles.


RESULTS
CT showed statistically significant differences in wall irregularity and soft-tissue thickening between malignant and benign cases (p < 0.05). Short diameter of mucoceles, attenuation of intraluminal contents, maximal wall thickness, calcifications, internal septations, periappendiceal fat stranding, intraperitoneal free fluid, and pseudomyxoma peritonei in the lesions did not differ significantly between the benign and malignant groups (p > 0.05).


CONCLUSIONS
Differentiating malignant from benign mucoceles can be difficult with CT. Irregular walls and soft-tissue thickening are features most likely to be associated with malignancy.
1 Department of Radiology, Central Hospital of Minhang District, 170 Xinsong Rd, Shanghai, 201199, China.
Hao
H
Wang
Yong-Qi
YQ
Chen
Ran
R
Wei
Qing-Bing
QB
Wang
Bin
B
Song
Cang-Yi
CY
Wang
Bei
B
Zhang
D000328:Adult; D000368:Aged; D001063:Appendiceal Neoplasms / Q000000981:diagnostic imaging*; D002429:Cecal Diseases / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009078:Mucocele / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult