[Appendiceal mucocele. Apropos of 6 cases].

Abstract

Appendicular mucocele is a rare lesion presenting a combination of several histological lesions. It generally ruptures into the peritoneum and rarely into the retroperitoneum. The objective of this study was to examine the various radiological appearances of appendicular mucocele and to report three cases of mucocele which ruptured into the retroperitoneum. This retrospective series of 6 cases of histologically confirmed appendicular mucocele was collected by the Central Radiology Department of Ibn Rochd University Hospital in Casablanca. The mean age of the patients was 61.6 years (33 years-77 years) and the sex ratio was 4/2. A plain abdominal X-ray and ultrasonography were performed in all patients. Five patients were examined by CT scan and two underwent a barium enema. Five out of six mucoceles ruptured: into the peritoneal cavity in 2 cases with gelatinous ascites and into the retroperitoneum in 3 cases. The plain abdominal X-ray showed a mass in the right flank, which was calcified in 2 cases. Ultrasonography and CT scan were suggestive of the diagnosis of appendicular mucocele in only two cases. The case of non ruptured mucocele consisted of a clearly delimited, thin-walled collection. A loculated effusion with scalloping on the liver was observed in the two cases of gelatinous ascites. In the three cases of mucocele rupturing into the retroperitoneum, ultrasonography and CT scan showed a loculated retroperitoneal collection. This collection extended into the right psoas in 2 out of 3 cases. Gelatinous ascites is the usual complication of appendicular mucocele; but in rare cases of mucocele of a retrocaecal appendix, the mucus may enter the retroperitoneum.