*A 12-year-old boy presents with a 24-hour history of periumbilical pain that has migrated to the right iliac fossa. He has nausea, vomiting, and tenderness in the right lower quadrant. A provisional diagnosis of acute appendicitis is made, and he is taken for surgery. Intraoperatively, the appendix appears normal. Further exploration reveals a 4-cm inflamed outpouching arising from the antimesenteric border of the ileum, about 60 cm proximal to the ileocecal junction.*

Reading File

Finding Sources

Reading File

Loading Image

Finding Sources

I now have comprehensive, authoritative information from multiple textbooks. Here is the full clinical analysis:

Meckel's Diverticulum - Complete Clinical Analysis

Diagnosis

This boy has Meckel's diverticulitis. The intraoperative findings are pathognomonic:

Outpouching from the antimesenteric border of the ileum
Located ~60 cm proximal to the ileocecal junction
Inflamed (diverticulitis)
Normal appendix

This is the most common congenital anomaly of the gastrointestinal tract.

Embryology

Meckel's diverticulum results from incomplete closure (failed involution) of the omphalomesenteric (vitelline) duct - the structure that connects the midgut to the yolk sac during fetal development. It is a true diverticulum, meaning it contains all three layers of the bowel wall (mucosa, muscularis, serosa) and has its own blood supply (a branch of the superior mesenteric artery).

Robbins, Cotran & Kumar Pathologic Basis of Disease, p. 1492
Sabiston Textbook of Surgery, p. 2535

The "Rule of 2s"

A classic mnemonic summarizing its features:

Feature	Value
Prevalence in population	~2%
Distance from ileocecal valve	~2 feet (60 cm)
Length	~2 inches (5 cm)
Male:female ratio	2:1
Age most often symptomatic	By age 2 years
Lifetime risk of symptoms	~2% (only ~4% are ever symptomatic)

This patient's diverticulum is 4 cm long and located 60 cm proximal to the ileocecal junction - perfectly consistent with the rule of 2s.

Bailey and Love's Short Practice of Surgery, 28th Ed, p. 1333
Robbins, Cotran & Kumar, p. 1492-1503

Gross Pathology

This is what a Meckel's diverticulum looks like on gross pathology (from Robbins):

Meckel's diverticulum - gross specimen showing blind pouch on antimesenteric side of ileum

Meckel's diverticulum: the blind pouch is located on the antimesenteric side of the small bowel

Heterotopic Mucosa

In approximately 20-50% of cases, the diverticulum contains ectopic (heterotopic) tissue:

Gastric mucosa - most common (the parietal cells secrete HCl, causing acid-induced peptic ulceration of the adjacent ileal mucosa)
Pancreatic mucosa - second most common
Rarely: colonic mucosa

The mucus-secreting cells of ectopic gastric mucosa are the basis for the Meckel's scan (Tc-99m pertechnetate scintigraphy), described below.

Sabiston, p. 2535
Robbins, p. 1503

Clinical Presentations / Complications

Complication	Details
Diverticulitis	Clinically indistinguishable from appendicitis (as in this case) - presents with periumbilical pain migrating to RLQ, nausea, vomiting
Haemorrhage	Most common symptomatic presentation in children <2 years; caused by peptic ulceration from ectopic gastric mucosa; presents as painless dark rectal bleeding or melaena
Intestinal obstruction	Via: (1) volvulus around a fibrous band connecting diverticulum apex to umbilicus, (2) intussusception (Meckel's acts as lead point - ileoileal or ileocolic), (3) Littre's hernia (incarceration in inguinal hernia)
Perforation	Follows diverticulitis; may resemble perforated duodenal ulcer
Chronic ulceration	Periumbilical pain (midgut origin)
Neoplasm	Rare (0.5-3.2%); NETs most common (33-44%), followed by leiomyosarcoma, adenocarcinoma, GIST

Key surgical teaching point: When a normal appendix is found during exploration for suspected appendicitis, the distal ileum must be examined for an inflamed Meckel's diverticulum - exactly as occurred in this case.

Bailey and Love's, p. 1333-1334
Sabiston, p. 2540-2544

Diagnosis (Preoperative, if not explored surgically)

Plain abdominal X-ray, CT, ultrasound: rarely diagnostic
Tc-99m pertechnetate scintigraphy (Meckel's scan): Investigation of choice in children
- Pertechnetate is taken up by mucus-secreting cells of ectopic gastric mucosa
- Sensitivity ~85%, specificity ~95%, accuracy ~90% in children
- Sensitivity drops to ~63% in adults (less ectopic gastric tissue)
- Cimetidine pre-treatment enhances sensitivity (reduces secretion, increases radionuclide retention)
Mesenteric arteriography: useful in acute haemorrhage
Double-balloon endoscopy, barium contrast: for false-negative scans
Sabiston, p. 2553-2555

Surgical Management

Symptomatic Meckel's diverticulum requires prompt surgery:

Diverticulectomy - for non-bleeding Meckel's diverticulitis (hand-sewn or stapled across the base in a diagonal/transverse line to prevent stenosis)
Segmental ileal resection - required for haemorrhage (bleeding ulcer is in the adjacent ileum, not the diverticulum itself); also required for complications such as volvulus/gangrene
Laparoscopic vs. open: retrospective studies show equivalent outcomes

Incidentally found (asymptomatic) Meckel's diverticulum:

In children: generally recommended to resect
In adults: controversial; resection considered if risk factors are present:
- Age <50 years
- Male sex
- Length >2 cm
- Presence of ectopic tissue or palpable abnormalities
Sabiston, p. 2560-2568
Bailey and Love's, p. 1333-1334

Summary for This Case

Feature	This Patient
Age	12 years (pediatric - higher risk if symptomatic)
Diagnosis	Meckel's diverticulitis mimicking acute appendicitis
Finding	4-cm diverticulum, antimesenteric border, 60 cm from IC junction - classic
Management	Diverticulectomy (non-bleeding, so simple excision at the base is appropriate)
Underlying mechanism	Failed involution of omphalomesenteric duct
Potential ectopic tissue	Ectopic gastric or pancreatic mucosa possible (~20-50%)

This is a shared conversation. Sign in to Orris to start your own chat.