What is the best next step for a patient with suspected liver metastases who has not been biopsied and now presents with a clearly visualized hepatic lesion on triple‑phase computed tomography?

Management of Non-Biopsied Liver Metastases on Triple-Phase CT

For a patient with suspected liver metastases presenting with a gross lesion on triple-phase CT, proceed directly to multidisciplinary tumor board discussion to determine treatment strategy without routine biopsy, as imaging diagnosis is sufficient in most cases and biopsy carries significant risks without changing management in the majority of patients. 1, 2

Immediate Diagnostic Steps

Confirm the Clinical Context

• Establish whether the patient has known extrahepatic malignancy, as this fundamentally changes the diagnostic approach and probability of metastatic disease 2
• In patients with known primary malignancy, 91% of liver lesions are malignant, though benign lesions still occur in nearly 30% of cancer patients 1, 2
• Document any history of chronic liver disease or cirrhosis, as this shifts the differential diagnosis toward hepatocellular carcinoma rather than metastases 1, 2

Optimize Imaging Characterization

• If the triple-phase CT shows indeterminate features or diagnostic uncertainty remains, order contrast-enhanced MRI with extracellular gadolinium agents as the next step 2, 3
• MRI establishes a definitive diagnosis in 95% of liver lesions versus 74-95% for CT, and only 1.5% require further imaging after MRI versus 10% after CT 2, 3
• For patients with known malignancy, MRI demonstrates 90.8-95.4% sensitivity and 83.7-89.8% specificity for detecting malignant lesions 2
• Contrast-enhanced ultrasound (CEUS) is an alternative option that correctly characterizes 95% of lesions overall and 98% of metastases in patients with indeterminate CT findings 2

Biopsy Decision Algorithm

When to Avoid Biopsy

• Do not perform routine biopsy if imaging shows typical features of metastatic disease in a patient with known primary malignancy, as imaging diagnosis is sufficient for treatment planning 1, 2
• Avoid biopsy when the lesion appears resectable and surgical treatment is planned, as biopsy does not change management and carries a 9-12% bleeding risk 1, 2
• Biopsy has a 30% false-negative rate for small lesions and a 0.1-0.7% risk of needle-track seeding 1, 3

When Biopsy Is Indicated

• Perform image-guided biopsy only when imaging remains indeterminate after MRI or when histopathology is required for molecular testing to guide systemic therapy selection 1, 2
• Biopsy is necessary when the diagnosis could be lymphoma or another malignancy requiring histopathologic confirmation for treatment planning 1
• In patients with known primary malignancy, biopsy may be needed if imaging suggests a different primary cancer (occurs in 5% of cases) 1
• Use CEUS guidance to increase technical success rate from 74% to 100% for biopsy of indeterminate lesions 1, 2

Treatment Planning Pathway

Multidisciplinary Evaluation

• Refer immediately to multidisciplinary tumor board including hepatobiliary surgery, medical oncology, and interventional radiology to determine resectability and treatment strategy 4
• Complete staging evaluation must include assessment of extrahepatic disease before considering any liver-directed therapy 5, 4
• For colorectal liver metastases, surgical resection offers the only potential for cure with 5-year survival rates of 25-46% in selected patients 5, 6

Resectability Assessment

• Determine if complete resection is feasible based on number, size, and distribution of liver metastases on imaging 5, 4
• Evaluate adequacy of future liver remnant and vascular/biliary involvement 4, 6
• Consider neoadjuvant chemotherapy to downsize lesions if borderline resectable 5, 6

Common Pitfalls to Avoid

• Do not delay treatment planning while pursuing biopsy confirmation when imaging is diagnostic and the patient has known primary malignancy 1, 2
• Do not apply HCC diagnostic criteria (LI-RADS) to patients without chronic liver disease or cirrhosis, as this leads to misdiagnosis 2
• Do not order single-phase CT or non-contrast imaging for solid lesion characterization, as this is inadequate 2
• Do not assume all liver lesions in cancer patients are metastases—up to 30% are benign and require proper characterization to avoid overtreatment 1, 2
• Avoid biopsy of hypervascular lesions without careful risk-benefit assessment due to 9-12% bleeding risk 1, 3