Three Cases of Appendiceal Mucocele: Specific Ultrasonographic Findings

Abstract

Appendiceal mucocele is rarely seen in the clinic. Rather, it is found incidentally or on examination of pain or a palpable mass in the right lower quadrant. We describe three cases of appendiceal mucocele, each of which produced characteristic ultrasound images. Case 1 occurred in a 19-year-old man who complained of a palpable mass in the right lower quadrant of the abdomen. The ultrasonogram showed a 9.1×3.7 cm hypoechoic mass with a calcified wall and internal echogenic layers resembling the cross section of an onion in the right paracolic gutter. Case 2 was that of a 70-year-old woman with discomfort in the right lower quadrant. Abdominal examination detected a palpable mass with no tenderness in the area. The ultrasonogram showed a 9.6×3.1 cm cystic mass with internal echogenic layers similar to those in Case 1 in the medial part of the ileocecum. Case 3 occurred in a 59-year-old woman who complained of pain in the right lower quadrant. Abdominal examination detected a palpable mass accompanied by tenderness in the right lower quadrant. The ultrasonogram showed a multiple concentric ring sign and a cup-and-ball shaped cystic mass in the right upper abdomen, which indicated intussusception with an appendiceal mucocele. The ultrasonogram after barium enema reduction showed a 2.5×2.0 cm oval mass in the cecum connected with the dilated appendix 1.1 cm in diameter. Ultrasonography proved useful for diagnosing appendiceal mucocele.