How do you get a biopsy of the pancreatic head

Biopsy of the Pancreatic Head

For pancreatic head masses, endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) using a 25-gauge or 22-gauge needle via the transduodenal approach is the preferred method, as it provides superior diagnostic accuracy, lower risk of tumor seeding compared to percutaneous approaches, and avoids the technical difficulties associated with larger needles in this location. 1

When Biopsy is Actually Needed

Critical distinction: Biopsy is NOT routinely required for all pancreatic head lesions 1, 2:

• Skip biopsy entirely if the patient has a resectable lesion and is a good surgical candidate—proceed directly to surgery 2
• Biopsy is mandatory only in unresectable cases or when neoadjuvant therapy is planned 1
• Biopsy should be performed when imaging findings are ambiguous and cannot distinguish between benign and malignant disease 1
• A negative biopsy should never delay surgery when clinical suspicion for malignancy is high 2

Optimal Technique: EUS-FNA

Needle Selection for Pancreatic Head Lesions

Use smaller gauge needles for transduodenal sampling 1:

• 25-gauge needle: Diagnostic accuracy of 91.7% overall and 83.3% specifically for pancreatic head/uncinate lesions 1
• 22-gauge needle: Diagnostic accuracy of 79.7% overall and 58.3% for head/uncinate lesions 1
• Avoid 19-gauge needles for pancreatic head masses—they have significantly higher technical failure rates (8.3% diagnostic accuracy for head lesions) due to rigidity when navigating the transduodenal route 1

Technical Approach

• Access route: Transduodenal approach from the duodenum for pancreatic head and uncinate process lesions 1, 3
• Number of passes: Median of 3 needle passes typically required 4
• Real-time guidance: Use curvilinear echoendoscope with real-time visualization during needle advancement 4, 3

Diagnostic Performance

EUS-FNA demonstrates excellent diagnostic characteristics 4, 3:

• Sensitivity for malignancy: 70-94% 2, 4
• Specificity: Highly specific with essentially no false-positive diagnoses 4, 3
• Safety profile: Excellent with no significant procedure-related complications in major series 1, 4

Alternative Approaches and When to Avoid Them

Percutaneous Biopsy

Strongly avoid percutaneous approaches for potentially resectable pancreatic head lesions 1, 5, 2:

• Higher risk of peritoneal tumor seeding compared to EUS-guided approach 1, 5
• Should only be considered for metastatic lesions (liver, distant sites) under ultrasound or CT guidance 1
• If percutaneous biopsy must be performed, avoid traversing normal pancreatic tissue to minimize pancreatitis risk 6
• Use 19-gauge needle with coaxial technique if percutaneous approach is unavoidable 6

ERCP Brushings

Do not rely on ERCP for tissue diagnosis 1:

• High specificity but unacceptably low sensitivity 1
• ERCP should be reserved solely for biliary decompression, not diagnostic purposes 1
• Preoperative biliary stenting increases serious complications and should only be performed if surgery cannot be done expeditiously 1

Histology vs. Cytology Considerations

When Core Tissue is Needed

Standard FNA provides cytology, which may be insufficient for 1:

• Stromal cell tumors requiring tissue architecture for diagnosis 1
• Lymphomas requiring morphologic assessment 1
• Situations where definitive diagnosis of benign disease is needed 1

Obtaining Histologic Samples

If histology is required, the 19-gauge ProCore needle (now available in 22-gauge platform) can obtain core specimens 1:

• Diagnostic accuracy >90% for histologic samples 1
• The 22-gauge ProCore platform facilitates easier transduodenal sampling compared to 19-gauge 1
• Standard 19-gauge needles are too stiff for transduodenal routes and should be avoided for pancreatic head lesions 1

Common Pitfalls to Avoid

• Never perform percutaneous biopsy on potentially resectable lesions due to seeding risk 1, 5, 2
• Do not delay surgery for tissue diagnosis in good surgical candidates with resectable disease 2
• Avoid 19-gauge standard needles for transduodenal sampling—use 22G or 25G instead 1
• Do not use negative biopsy as reason to abandon surgery when clinical suspicion remains high 2
• Avoid routine preoperative biliary stenting—it increases complications without benefit if surgery can proceed promptly 1