Should a biopsy be performed on a pancreatic cystic lesion?

From the Guidelines

Yes, a biopsy should be performed on a pancreatic cystic lesion if it exhibits high-risk features, such as size ≥3 cm, a dilated main pancreatic duct, or the presence of an associated solid component 1. The decision to biopsy is typically based on the size, location, and characteristics of the cyst, as well as the patient's symptoms and risk factors.

Indications for Biopsy

• Larger cysts (greater than 3 cm) or those with suspicious features, such as thick walls, septations, or main pancreatic duct dilation, are more likely to require endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) biopsy 1.
• The presence of a solid component increases the risk of malignancy approximately 8 times, making EUS-FNA biopsy a reasonable option 1.
• A systematic review of the literature suggests that cyst size ≥3 cm, a dilated main pancreatic duct, and the presence of a solid component are factors associated with increased risk of malignancy 1.

Approach to Biopsy

• For asymptomatic patients with small pancreatic cysts (less than 3 cm), imaging surveillance may be recommended, with MRI being the preferred surveillance imaging modality over computed tomography 1.
• EUS-FNA biopsy is often performed for larger cysts or those with suspicious features, with a sensitivity of approximately 60% and a specificity of 90% 1.
• In some cases, a molecular analysis of the cyst fluid may be conducted to assess for genetic mutations associated with pancreatic cancer, such as KRAS or GNAS 1.

Considerations

• The risk of malignant transformation in pancreatic cysts is estimated to be 0.24% per year, varying according to histologic subtype 1.
• The overall risk that an incidental pancreatic cyst is malignant is very low, with a 10 in 100,000 chance of being a mucinous invasive malignancy and a 17 in 100,000 chance of being a ductal carcinoma 1.
• It is essential to approach each case individually, considering the patient's overall health, preferences, and the potential risks and benefits of biopsy and subsequent treatment 1.

From the Research

Biopsy for Pancreatic Cystic Lesions

• The decision to perform a biopsy on a pancreatic cystic lesion depends on various factors, including the size, location, and characteristics of the lesion, as well as the patient's overall health and risk factors 2, 3, 4.
• Endoscopic ultrasound with fine-needle aspiration (EUS-FNA) biopsy can be used to assess the risk of malignancy in pancreatic cystic lesions, particularly those with complex features or high malignant potential 2, 4, 5.
• The use of EUS-FNA biopsy has been shown to be effective in diagnosing pancreatic cystic lesions, with a high degree of accuracy and minimal side effects 5.
• However, the management of pancreatic cystic lesions is often individualized and depends on various guidelines, including the size and characteristics of the lesion, as well as the patient's overall health and risk factors 2, 3, 4.

Indications for Biopsy

• Biopsy may be indicated for pancreatic cystic lesions that are symptomatic, have high malignant potential, or are larger than 3 cm 2, 3.
• Lesions with complex features, such as solid masses or nodules, may also require biopsy to assess the risk of malignancy 3, 4.
• EUS-FNA biopsy may be used to supplement magnetic resonance imaging (MRI) findings for cysts that remain indeterminate or have concerning features on imaging 3.

Diagnostic Accuracy

• EUS-FNA biopsy has been shown to have a high degree of diagnostic accuracy for pancreatic cystic lesions, with a sensitivity and specificity of over 90% in some studies 5.
• The use of cyst fluid markers, such as carcinoembryonic antigen (CEA) and glucose, can also help distinguish between mucinous and non-mucinous cysts 3, 4.