PA24.1-9 | Hepatobiliary System — Case Study

CLINICAL SCENARIO

A peer-reviewed case-study assignment covering the clinicopathological workup of chronic alcohol-related liver disease complicated by cirrhosis, portal hypertension, and hepatocellular carcinoma surveillance. Aligned to NMC CBUC 2024 competencies PA24.1–PA24.9.

Section 1 — Interpreting Liver Function Tests and Bilirubin Fractions

Analyse Mr. Rajan's LFT panel systematically. (a) Classify the jaundice as pre-hepatic, hepatic, or post-hepatic based on the bilirubin fractions, and justify your classification. (b) Explain the significance of the AST:ALT ratio of 2.1 in the context of the clinical history. (c) Interpret the low albumin and elevated INR as markers of hepatic synthetic dysfunction — what do they tell you about the functional reserve of Mr. Rajan's liver?

Guidance: Focus on the pathophysiology of each abnormal value, not just normal/abnormal labelling. Connect bilirubin conjugation capacity to hepatocyte mass. The AST:ALT ratio is a key discriminator — explain the biochemical reason it is elevated in alcohol-related disease (mitochondrial AST release, pyridoxal-5'-phosphate depletion). For albumin and INR, link to specific hepatic synthetic pathways (albumin synthesis, clotting factor synthesis in the liver). Word target: 200–250 words.

Section 2 — Establishing the Aetiology

Using the history, serological results, and laboratory pattern, construct a differential diagnosis for Mr. Rajan's chronic liver disease. (a) Which single diagnosis best explains the complete clinical picture, and why? (b) Critically evaluate the role of each serological test in excluding alternative aetiologies (HBV, HCV, autoimmune hepatitis, primary biliary cholangitis, Wilson disease, haemochromatosis). (c) How does the mildly elevated ferritin fit into the alcohol-related diagnosis without invoking hereditary haemochromatosis?

Guidance: Use a systematic approach: list the differentials and then narrow using the available data. The negative viral serology, autoimmune markers, and normal ceruloplasmin must each be addressed. Note that GGT is preferentially elevated in alcohol-related liver disease and in cholestasis — discuss which driver is primary here. Alcohol-induced secondary iron loading (elevated ferritin without transferrin saturation elevation) is a common exam discriminator. Word target: 250–300 words.

Section 3 — Pathology of Cirrhosis

Describe the pathological basis of cirrhosis as it would be seen in Mr. Rajan's liver. (a) Define cirrhosis precisely in morphological terms. (b) Outline the sequence of events from chronic alcohol injury → hepatocellular death → inflammatory response → fibrogenesis → regenerative nodule formation, naming the key cells and mediators at each step. (c) Describe how macro- and micronodular patterns of cirrhosis are distinguished, and identify which pattern predominates in alcohol-related disease.

Guidance: This section must demonstrate mechanistic understanding, not a list of facts. Key players: hepatic stellate cells (Ito cells), TGF-β1, PDGF, the Disse space, sinusoidal capillarisation. Distinguish early (macrovesicular steatosis → steatohepatitis → pericentral/pericellular fibrosis → bridging fibrosis → cirrhosis) from the end-stage morphology. Alcohol-related cirrhosis is classically micronodular initially (Laënnec cirrhosis), progressing to mixed. Gross and microscopic descriptions both expected. Word target: 300–350 words.

Section 4 — Portal Hypertension and Its Complications

Mr. Rajan has portal hypertension, ascites, and oesophageal variceal bleeding. (a) Explain the haemodynamic mechanism by which cirrhosis leads to portal hypertension, distinguishing pre-sinusoidal, sinusoidal, and post-sinusoidal resistance components. (b) For each of the following complications, describe the underlying pathophysiological mechanism and link it to specific clinical or laboratory finding in this case: (i) oesophageal varices and variceal haemorrhage; (ii) ascites; (iii) splenomegaly with hypersplenism (thrombocytopaenia). (c) Classify the cause of portal hypertension in this case using the pre-, intra-, and post-hepatic framework.

Guidance: Mechanistic answers required. For ascites: sinusoidal hypertension → transudation into the peritoneum + RAAS activation + hypoalbuminaemia → reduced oncotic pressure — address all three arms. For varices: porto-systemic collateral circulation anatomy (left gastric → oesophageal plexus → azygos), variceal wall tension (LaPlace's law). Hypersplenism: congestive splenomegaly → sequestration. Mention the HVPG (hepatic venous pressure gradient) concept as the gold standard for measuring portal pressure. Word target: 300–350 words.

Section 5 — Hepatic Failure Manifestations

Mr. Rajan has grade I asterixis and hyponatraemia. (a) Define hepatic encephalopathy (HE) and describe its pathogenesis with particular reference to ammonia, astrocyte dysfunction, and the role of gut bacteria. (b) Explain why hyponatraemia develops in decompensated cirrhosis — distinguish dilutional from sodium-depletional mechanisms. (c) List four other systemic manifestations of hepatic failure (beyond HE and hyponatraemia) seen in this case or commonly expected at this stage, and explain the pathological basis of each.

Guidance: HE pathogenesis: portal-systemic shunting of ammonia → astrocyte swelling (Alzheimer type II astrocytosis) → cerebral oedema + neurotransmitter imbalance. Hyponatraemia here is dilutional (effective arterial underfilling → ADH release). The four additional manifestations should be drawn from the case data (palmar erythema, spider naevi, coagulopathy, hypoalbuminaemia) — each needs a mechanism, not just a name. Word target: 250–300 words.

Section 6 — HCC Risk Stratification and Surveillance

Mr. Rajan's AFP is 42 ng/mL and the liver ultrasound shows no focal lesion. (a) Explain why cirrhosis is a major pre-malignant condition for hepatocellular carcinoma (HCC), describing the molecular and cellular mechanisms underlying malignant transformation. (b) Critically interpret the AFP value — does it confirm, exclude, or warrant further investigation for HCC? What are the limitations of AFP as a screening marker? (c) Design a structured 12-month HCC surveillance protocol for Mr. Rajan, specifying the modality, interval, and the AFP threshold at which further imaging is triggered, based on current evidence.

Guidance: Mechanisms of HCC in cirrhosis: regenerative nodule → dysplastic nodule → early HCC → progressed HCC; telomere shortening, TP53 mutations, Wnt/β-catenin pathway, chronic oxidative stress. AFP: sensitivity ~60%, specificity ~80% at a 20 ng/mL cut-off; values 10–200 ng/mL in cirrhosis without HCC (hepatic regeneration, active hepatitis, germ cell tumours). Surveillance standard: 6-monthly liver ultrasound ± AFP; LIRADS/AASLD criteria for diagnostic workup when a nodule is found. Do not recommend multiphasic CT/MRI as the primary screening tool (cost, radiation, availability). Word target: 250–300 words.

PEER REVIEW

You will be assigned one peer's submission to review. Your peer review is a learning exercise — it should be constructive, specific, and evidence-based. Follow these steps:

1. Read the full submission first before writing any comments.
2. Evaluate each section independently against the criteria below:
- Is the bilirubin classification correct and mechanistically justified?
- Is the aetiological reasoning systematic and evidence-based?
- Is the cirrhosis pathology mechanistically described (not just listed)?
- Are all three portal hypertension complications mechanistically explained?
- Are HE and hyponatraemia pathogenesis explained, not just named?
- Is the AFP interpretation nuanced and is the surveillance protocol evidence-based?
3. Write structured feedback with:
- Two specific strengths — quote or paraphrase the part of the submission that demonstrates the strength.
- Two specific suggestions for improvement — be precise about what is missing or incorrect and how it could be corrected.
4. Assign a provisional mark out of 30 for your peer's submission based on the rubric criteria. A brief justification (2–3 sentences) is required.
5. Tone: Be collegial and professional. Peer review is not grading — it is formative feedback between colleagues.