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PA23.3-4 | Peptic Ulcer Disease & Gastric Carcinoma — SDL Guide (Part 2)

Gross Morphology — Benign vs Malignant Gastric Ulcer

Benign vs Malignant Gastric Ulcer: Gross Morphology

Distinguishing a benign peptic ulcer from a malignant (carcinomatous) ulcer on endoscopy and gross pathology is a high-yield clinical skill.

Benign peptic ulcer (classic features):
• Small, usually < 2 cm (duodenal nearly always < 1.5 cm).
• Punched-out appearance — circular or oval, with sharply demarcated perpendicular walls (like a cookie-cutter defect).
• Clean, flat base — often grey-white, covered by a thin fibrinous slough.
• Radiating mucosal folds converge toward the ulcer margin — a key sign of benign healing.
• Edges are smooth, not heaped; surrounding mucosa is pliable.

Malignant gastric ulcer (suspicious features — Mnemonic: MENACE):
• Often > 2-3 cm.
• Heaped-up, irregular, nodular margins — rolled, everted edges.
• Necrotic, shaggy, dirty base.
• Mucosal folds are interrupted or fused (do not converge cleanly).
• Surrounding mucosa is rigid, indurated.
• Location: body/fundus rather than antrum/lesser curvature raises suspicion.

> Clinical rule: ALL gastric ulcers require biopsy (multiple, from edges AND base). Duodenal ulcers are virtually never malignant and biopsy is not mandatory unless atypical.

Gross Comparison of Benign and Malignant Gastric Ulcers

Microscopic Anatomy — The Four Zones of a Chronic Peptic Ulcer

Four Zones of a Chronic Peptic Ulcer

On histological section through the base of a chronic peptic ulcer, four concentric zones are seen from the luminal surface inward. This is a classical exam question.

Zone 1 — Necrotic (superficial)
Thin layer of eosinophilic necrotic debris, fibrin, and dead cells. This is the ulcer floor visible to the naked eye.

Zone 2 — Inflammatory (neutrophilic/exudative)
Dense neutrophilic infiltrate with fibrinous exudate. Active inflammation responsible for symptoms.

Zone 3 — Granulation tissue
Vascular loops, fibroblasts, and a mixed inflammatory infiltrate (lymphocytes, plasma cells, macrophages). This is the healing layer — what you want to see on follow-up biopsy.

Zone 4 — Scar (fibrosis)
Dense collagen replacing the muscularis propria. The deepest zone. Explains why healed ulcers may leave a permanent indentation and why obstructive complications occur (pyloric fibrosis → gastric outlet obstruction).

Remember: N-I-G-S (Necrotic → Inflammatory → Granulation → Scar), from lumen to depth.

Chronic Peptic Ulcer: Four Histologic Zones

Complications of Peptic Ulcer Disease

Complications of Peptic Ulcer Disease

PUD complications are best learned systematically:

1. Haemorrhage (bleeding) — most common complication (~15-20% of patients). Posterior duodenal ulcers erode the gastroduodenal artery → major haemorrhage. Presents as haematemesis or melaena. Life-threatening: requires endoscopic haemostasis ± surgery.

2. Perforation — ulcer penetrates through all layers → gastric contents spill into peritoneal cavity → chemical peritonitis → bacterial peritonitis. Anterior duodenal ulcers perforate most often. Classic presentation: sudden, severe epigastric pain ('board-like abdomen'); erect CXR shows free air under diaphragm (pneumoperitoneum). Surgical emergency.

3. Penetration — ulcer erodes into an adjacent organ (without free perforation). Pancreatic penetration → pancreatitis; pain radiates to the back and is not relieved by antacids.

4. Pyloric/duodenal obstruction — fibrosis of the pyloric channel → gastric outlet obstruction. Presents with recurrent vomiting of undigested food, succussion splash, hypochloraemic hypokalaemic metabolic alkalosis. Endoscopic balloon dilatation or surgery.

5. Malignant transformation — duodenal ulcers essentially NEVER become malignant (a key distinguishing fact). Gastric ulcers have a small but real risk (<1%); this is why biopsy is mandatory.

> Clinical pearl: H. pylori eradication (triple/quadruple therapy) heals 90% of H. pylori-positive ulcers and prevents recurrence. Test-and-treat is now the standard of care.