How are hepatic and pancreatic lesions diagnosed as malignant neoplasms (cancer)?

From the Guidelines

Diagnosing hepatic and pancreatic lesions as cancer requires a multi-step approach involving imaging studies and tissue sampling, with the most recent and highest quality study recommending CT scans and MRI for initial staging, followed by EUS for complementary information and biopsy 1. The diagnosis of hepatic and pancreatic lesions as cancer typically involves:

• Imaging techniques such as ultrasound, CT scans, MRI, or endoscopic ultrasound (EUS) to reveal abnormal masses or structural changes
• Biopsy, where a sample of tissue is collected from the lesion and examined microscopically by a pathologist, which can be performed via fine needle aspiration (FNA), core needle biopsy, or during surgery
• Additional laboratory tests, including tumor markers like alpha-fetoprotein (AFP) for liver cancer or CA 19-9 for pancreatic cancer, though these are not diagnostic on their own
• Molecular and genetic testing of the tissue sample to identify specific mutations or biomarkers that can confirm malignancy and guide treatment decisions Key points to consider:
• CA 19-9 is the most useful tumor marker in pancreatic cancer, but it is not useful for primary diagnosis 1
• EUS provides complementary information and allows biopsy of the tumor, with a high diagnostic accuracy of up to 95% when carried out by an experienced cytopathologist 1
• MRI should be discussed, especially in cystic lesions, and can be useful for solving problems such as the detection of hepatic lesions that cannot be characterized by CT 1
• The imaging work-up must determine the tumor size and precise burden, as well as arterial and venous local involvement, to guide treatment decisions 1

From the Research

Diagnostic Techniques for Hepatic and Pancreatic Lesions

• Imaging techniques such as computed tomography (CT) scans, magnetic resonance imaging (MRI), and endoscopic ultrasound (EUS) are used to diagnose pancreatic cancer 2, 3.
• CT scans have a high sensitivity for detecting pancreatic carcinoma, ranging from 89% to 97% 3.
• EUS is superior to CT and MRI in detecting small tumors and can also localize lymph node metastases or vascular tumor infiltration with high sensitivity 3.
• EUS-guided fine-needle aspiration biopsy is a safe and highly accurate method for tissue diagnosis of patients with suspected pancreatic carcinoma 4, 3.

Tumor Markers and Biomarkers

• Carbohydrate antigen 19-9 (CA 19-9) is a serum tumor marker that can be used to diagnose pancreatic cancer, but it has limited specificity 2, 5.
• Other biomarkers such as carcinoembryonic antigen and various other tumor markers have lower sensitivities than CA 19-9 2.
• Research is ongoing to discover novel serum biomarkers and explore their combination with CA 19-9 in the detection of pancreatic cancer 5.

Diagnostic Approach

• The combination of ultrasound and determination of CA 19-9 is recommended as the initial tests when pancreatic carcinoma is suspected 2.
• CT scans should also be performed if ultrasound is indeterminate or inconsistent with the clinical evaluation, as well as in patients with negative ultrasound but abnormal CA 19-9 2.
• EUS-FNA can be used as a definitive diagnostic test in the management of patients with a focal pancreatic lesion on CT scan/MRI but without obstructive jaundice 4.
• A combination of CT signs and MRI-DWI technique and MRCP can improve clinical pancreatic cancer diagnostic sensitivity 6.