A 62-year-old man presents with a 3-month history of painless jaundice, pale stools, and dark urine. He reports progressive weight loss of 8 kg over 2 months and mild epigastric discomfort. On examination, the abdomen is soft with a palpable gallbladder. Laboratory investigations show total bilirubin 12 mg/dL (direct 10 mg/dL), alkaline phosphatase 420 U/L, and ALT 85 U/L. Abdominal ultrasound reveals dilated intrahepatic bile ducts and a hypoechoic lesion in the pancreatic head measuring 3 cm. CT abdomen with contrast shows a hypodense mass in the pancreatic head with involvement of the superior mesenteric vein. What is the most appropriate next step in management?

Explanation

## Clinical Presentation & Diagnosis **Key Point:** Painless jaundice with weight loss in a patient >60 years is pancreatic cancer until proven otherwise. The classic triad is jaundice, weight loss, and epigastric pain (Courvoisier sign: palpable gallbladder with jaundice suggests distal biliary obstruction). **High-Yield:** CT imaging showing a pancreatic head mass with vascular involvement does NOT exclude resectability — it requires tissue confirmation before staging and treatment planning. ## Why EUS-FNA is the Next Step EUS-FNA is the gold standard for obtaining tissue diagnosis in suspected pancreatic cancer because: 1. **High diagnostic yield** — >95% sensitivity for masses >2 cm 2. **Minimally invasive** — avoids peritoneal seeding risk (unlike percutaneous biopsy) 3. **Real-time visualization** — allows assessment of vascular involvement and staging 4. **Guides treatment** — tissue diagnosis is mandatory before chemotherapy or surgery **Clinical Pearl:** Vascular involvement (SMV/portal vein) on imaging does NOT preclude resection if the vessel can be reconstructed. However, tissue diagnosis must precede any definitive treatment decision. ## Why Other Options Are Incorrect | Option | Why Not Chosen | |--------|----------------| | **Immediate surgery** | Tissue diagnosis is mandatory before pancreaticoduodenectomy; imaging alone is insufficient. Staging laparoscopy may be needed after diagnosis. | | **Palliative chemotherapy** | Chemotherapy requires confirmed diagnosis and performance status assessment; cannot be started on imaging alone. | | **PTC stent** | Biliary drainage is a supportive measure, not diagnostic. It may be needed later if jaundice persists, but does not establish diagnosis. | **Mnemonic: TISSUE before TREATMENT** — Always obtain tissue diagnosis (EUS-FNA) before committing to chemotherapy or surgery in pancreatic cancer. **Warning:** Do not confuse EUS-FNA with percutaneous biopsy — EUS is preferred because it avoids crossing the peritoneum and reduces tumor seeding risk.