A 42-year-old woman from Mumbai presents with acute RUQ pain, fever (38.5°C), and jaundice for 2 days. Laboratory values: WBC 14,000/μL, ALT 320 U/L, AST 280 U/L, bilirubin 4.2 mg/dL, ALP 180 U/L. Abdominal ultrasound shows a thickened gallbladder wall (5 mm), pericholecystic fluid, multiple echogenic foci within the gallbladder lumen with acoustic shadowing, and a dilated CBD (10 mm) with an echogenic focus impacted at the ampulla. What is the most likely diagnosis?

Explanation

## Clinical Presentation Analysis **Key Point:** The combination of acute RUQ pain, fever, jaundice, and imaging evidence of gallstones in the gallbladder AND a stone impacted at the ampulla defines acute cholecystitis complicated by choledocholithiasis. ## Diagnostic Criteria Met ### For Acute Cholecystitis (Tokyo Guidelines) 1. **Fever** ✓ (38.5°C) 2. **RUQ pain/tenderness** ✓ 3. **Imaging findings** ✓ - Thickened gallbladder wall (>3 mm is abnormal; 5 mm = moderate inflammation) - Pericholecystic fluid (edema/inflammation) - Gallstones with acoustic shadowing (confirms cholelithiasis) ### For Choledocholithiasis (Confirmed) 1. **Dilated CBD** (10 mm is borderline but abnormal in this acute context) 2. **Echogenic focus with acoustic shadowing at ampulla** — this is a **stone**, not sludge 3. **Jaundice + elevated bilirubin** — obstructive pattern ## Laboratory Pattern | Parameter | Finding | Interpretation | |-----------|---------|----------------| | WBC | 14,000 | Acute inflammation | | ALT/AST | 320/280 | Hepatocellular injury (mild) | | Bilirubin | 4.2 mg/dL | **Obstructive** (conjugated predominance expected) | | ALP | 180 | Cholestasis marker | | **Pattern** | **ALT > ALP** | **Hepatocellular > cholestatic** — but context is biliary obstruction | **High-Yield:** In choledocholithiasis, the **transaminases are often only mildly elevated** (unless there is concurrent pancreatitis). The **bilirubin and ALP are disproportionately elevated** relative to ALT/AST, reflecting obstruction. ## Imaging Pathophysiology ```mermaid flowchart TD A[Gallstone migration]:::outcome --> B[Stone lodges in cystic duct]:::action B --> C[Gallbladder inflammation & edema]:::outcome C --> D[Thickened wall + pericholecystic fluid]:::outcome A --> E[Some stones pass into CBD]:::action E --> F[Stone impacts at ampulla]:::action F --> G[CBD obstruction]:::outcome G --> H[Jaundice + elevated bilirubin]:::outcome B --> I[Fever + RUQ pain]:::outcome ``` ## Why NOT the Other Options **Acute pancreatitis** would show: - Elevated amylase/lipase (not mentioned; would be markedly elevated) - Gallbladder wall thickening from **edema**, not from cystic duct obstruction - Less prominent jaundice unless there is associated choledocholithiasis - The **stone at the ampulla** is the key finding — this is choledocholithiasis, not just pancreatitis **Ascending cholangitis** (without cholecystitis) would show: - Fever + jaundice + RUQ pain (Charcot triad) — ✓ present - BUT **no gallbladder wall thickening or pericholecystic fluid** — these indicate cholecystitis - Ascending cholangitis is a **complication** of choledocholithiasis, not the primary diagnosis here **Acute hepatitis** would show: - Marked elevation of transaminases (ALT > 1000 U/L typical) - Gallstones are **incidental**, not causative - No fever or RUQ tenderness ## Clinical Pearl **Choledocholithiasis occurs in ~10–15% of patients with cholecystitis.** The presence of a stone at the ampulla on ultrasound is diagnostic and warrants urgent ERCP for stone extraction, especially if there is evidence of ascending cholangitis (fever + Charcot triad). ## Management 1. **Immediate:** NPO, IV fluids, antibiotics (ceftriaxone + metronidazole or piperacillin-tazobactam) 2. **Urgent ERCP** with sphincterotomy and stone extraction (within 24–48 hours) 3. **Cholecystectomy** after acute inflammation resolves (within 2–4 weeks) or during same admission if feasible 4. Monitor for **ascending cholangitis** (fever + jaundice + RUQ pain) — if present, ERCP is emergent