Usually on third day, formation of appendicular mass is due to natural defense mechanism of body by which it try to localize the infection of appendix.
It is the walling off of inflamed or perforated appendix by greater omentum, oedematous caecum, oedematous terminal ileum and oedematous parities.
This mass is tender, variable in size with time and may have features of sub acute intestinal obstruction.
Differential diagnosis are carcinoma of caecum, tuberculosis of ileocaecal region, iliac lymphadenitis, twisted ovarian cyst or carcinoma, ectopic kidney etc.
Ultrasonography and CT scanning help in diagnosis.
Preferred treatment is conservative but experience surgeon can operate it, as surgery is difficult, bloody and dangerous, while appendicular abscess do need drainage per cutaneous are open.
Operative treatment is indicated in appendicular mass when rising pulse is on progress , increasing or spreading abdominal pain and increasing in size of mass or diagnosis is in doubt especially at extreme of age.
If it resolves on conservative treatment than interval appendicectomy is must.
If there is central collection of puss than it is called an appendicular abscess.
Pelvic abscess formation is an occasional complication of appendicitis, rectal examination reveals a boggy mass in the pelvis, ultrasound or CT scan will confirm and can be treated by transrectal drainage or ultrasound guided aspiration.
