Learning Radiology xray montage

Mucocoele of the Appendix

  • Overdistension of the appendix with mucous 2° to luminal obstruction by fecalith or foreign body, carcinoid or endometriosis
  • Mean age - 55 years
  • M:F = 1:4
  • Very rare
  • Associated with
    • Colonic adenocarcinoma
    • Mucin-secreting tumor of ovary
  • Clinical
    • Asymptomatic (25%)
    • Acute or chronic right lower quadrant pain
  • Globular, smooth-walled mass protruding into cecum
  • Peripheral, rim-like calcification may occur
  • Low attenuation content on CT
  • US
    • Purely cystic
    • Cystic with fine internal echoes
    • Complex cystic mass with high-level echoes
    • Gravity-dependent echoes = layering of protein macroaggregates / inspissated mucoid material
  • May rupture and produce pseudomyxoma peritonei
    • May produce bowel obstruction
  • Myxoglobulosis is a rare variant of mucocoele in which there are pearly white balls of mucous mixed with other mucous in a mucocoele
    • Usually asymptomatic
    • May present as appendicitis
    • Mass contains multiple small, rounded, nonlaminated calcified spheres 

 Mucocele of the appendix

Mucocele of the appendix - CT shows low attenuation
smooth-walled mass projecting into cecum in region of appendix