Synopsis
Explain how adaptation, cell injury, inflammation, repair, thrombosis and neoplasia create clinical disease, and interpret tissue diagnoses through representative sampling and integrated classification.
- Cells adapt to stress through hypertrophy, hyperplasia, atrophy and metaplasia; persistence or excess can progress to dysfunction, injury or neoplastic risk.
- Reversible injury disrupts energy, ion balance and organelles; irreversible injury crosses a point at which membrane and mitochondrial failure lead to cell death.
- Necrosis usually releases intracellular contents and provokes inflammation, while apoptosis packages regulated cell death with less surrounding reaction.
Reasoning priorities
Capture the lesion, interface and relevant normal tissue while preserving material for diagnosis.
A small or superficial sample may miss invasion, heterogeneity or necrosis; biopsy route and target should be planned with the treating and pathology teams.
Worked reasoning
Inputs: a superficial gastric biopsy shows marked atypia and ulceration. The fragments lack an intact epithelial–stromal interface and adequate underlying lamina propria, so stromal invasion cannot be assessed reliably; imaging suggests a deeper mass.
- Separate observed pathology from the clinical question: severe epithelial atypia is present, but fragmentation and the absent assessable epithelial–stromal interface and underlying stroma prevent reliable assessment of invasion in this specimen. Gastric carcinoma can invade within the mucosa; missing muscularis mucosae alone would not establish this limitation.
- Identify distortion mechanisms: ulceration and repair can produce reactive atypia, while fragmentation and missing tissue planes limit architecture.
- Integrate discordant imaging without letting it invent histology: a deeper mass raises concern and makes the superficial negative-for-invasion statement non-exclusionary.
- Report the highest supported epithelial abnormality with explicit sampling limitation rather than calling either benign repair or invasive carcinoma beyond evidence.
- Recommend multidisciplinary clinicoradiological correlation and suitably targeted repeat or definitive sampling when it will change management.
- Verify the next specimen by confirming lesion targeting, adequate depth and preservation, then reconcile morphology and imaging before final integrated classification.