Define Appendicular Mass. Describe its clinical features, management and treatment.

The Concept

An appendicular mass is the body's attempt to wall off an inflamed or perforating appendix. When appendicitis is not treated in the first day or two, the greater omentum and adjacent loops of small bowel adhere around the inflamed appendix, forming a palpable inflammatory mass in the right iliac fossa — usually about 3–5 days after the onset of symptoms. It represents a localised, contained process rather than free peritonitis, and this containment is what allows initial conservative treatment.

Clinical Features

The patient gives a history of a few days of right iliac fossa pain, and on examination there is a tender, ill-defined mass in the right iliac fossa. It must be distinguished from other right iliac fossa masses — a caecal carcinoma, Crohn's disease, or ileocaecal tuberculosis — which is why the colon is later investigated.

Management — the Ochsner-sherren Regimen

The classic management is conservative, the Ochsner-Sherren regimen: intravenous fluids, antibiotics, and close observation, with the size of the mass marked on the skin and the pulse, temperature and mass monitored. Most masses resolve on this regimen. An interval appendicectomy is then often performed about 6–8 weeks later, once the inflammation has settled, and a colonoscopy is done in older patients to exclude an underlying caecal cancer.

When Conservative Treatment Fails

The observation is not passive — it watches for deterioration. If the mass enlarges, the pain and fever worsen, or an abscess forms, conservative treatment is abandoned in favour of drainage of the appendicular abscess (radiological or surgical). Signs of spreading peritonitis similarly mandate surgery.

The Rationale for Conservatism

The reason for treating an appendicular mass conservatively rather than operating immediately is anatomical: the inflamed appendix is densely adherent within a mass of omentum and bowel, so early surgery is difficult and hazardous — it risks injuring adjacent structures and spreading contained infection. Allowing the inflammation to settle first makes a later (interval) appendicectomy safer and simpler.

The Bottom Line

An appendicular mass is thus a contained appendicitis, managed conservatively (Ochsner-Sherren) with interval appendicectomy and later colonoscopy in older patients to exclude a caecal cancer.

A Note on the Older Patient

In an older patient a right iliac fossa mass must never be assumed to be appendicular without excluding a caecal carcinoma, which can present identically. This is why an interval colonoscopy (or CT colonography) is arranged after the acute episode settles — the mass may resolve, but the underlying diagnosis must be secured.

Conservative management first, with interval appendicectomy.

• Appendicular mass = omentum + bowel walling off an inflamed/perforated appendix, ~3–5 days after onset (localised, contained).
• Tender right iliac fossa mass; distinguish from caecal cancer, Crohn's, ileocaecal TB.
• Managed conservatively (Ochsner-Sherren: IV fluids, antibiotics, observe, mark the mass) — most resolve.
• Interval appendicectomy ~6–8 weeks later; colonoscopy in older patients to exclude caecal cancer.
• Abandon conservative treatment and drain if it forms an abscess, enlarges, or peritonitis develops.