What features suggest discordance between imaging and pathology findings?

Features Suggesting Discordance Between Imaging and Pathology

Discordance exists when benign pathology results do not match suspicious imaging characteristics, such as a negative fine needle aspiration associated with a spiculated BI-RADS category 5 mass. 1

Key Features Indicating Discordance

Imaging-Pathology Mismatch Patterns

The most critical discordance pattern is benign pathology obtained from highly suspicious imaging findings (BI-RADS 4-5 lesions). 1 This represents the classic scenario where imaging characteristics strongly suggest malignancy but the biopsy yields benign results.

Specific examples of discordance include:

• Negative or benign biopsy from a spiculated mass (BI-RADS 5), which is highly suggestive of malignancy on imaging 1
• Benign pathology from lesions with suspicious microcalcifications showing fine pleomorphic or fine-linear branching patterns 1
• Benign results from masses with irregular margins or architectural distortion that appear suspicious on mammography or ultrasound 1

Technical Factors Contributing to Discordance

Inadequate tissue sampling is a major cause of discordance, occurring when the lesion is missed or only partially sampled during biopsy. 2

Technical issues include:

• Missed lesions - the biopsy needle completely misses the target lesion (44% of discordant malignant lesions in one study) 2
• Partial sampling - only the periphery of the lesion is sampled, missing the malignant component (44-48% of discordant cases) 2
• Geographic non-correlation - the biopsied area does not correspond to the imaging abnormality 1

Clinical and Imaging Characteristics

Discordance rates range from 1.9% to 5.8% across different biopsy techniques and institutions. 3, 4, 5, 2, 6 The malignancy rate in discordant cases is substantial, ranging from 27.5% to 36%, underscoring the critical importance of recognizing discordance. 2, 6

Specific imaging features that should raise concern for discordance when paired with benign pathology:

• BI-RADS 4C or 5 lesions (50-95% risk of malignancy) with benign biopsy results 7
• Spiculated or irregular masses with benign pathology 1
• Suspicious calcifications (fine pleomorphic, fine-linear branching) with benign results 1
• Solid masses with suspicious ultrasound features (irregular margins, posterior shadowing, taller-than-wide orientation) yielding benign pathology 1

Management Algorithm for Discordance

Immediate Actions Required

When discordance is identified, breast imaging should be repeated and additional tissue sampled or excised; surgical excision is recommended if pathology and imaging remain discordant. 1

The management pathway:

1. Repeat imaging to confirm the lesion characteristics and ensure the biopsy targeted the correct area 1
2. Obtain additional tissue sampling through repeat core needle biopsy or surgical excision 1
3. Proceed directly to surgical excision if discordance persists after repeat biopsy 1

Multidisciplinary Review

Implementation of radiologic-pathologic correlation conferences significantly reduces discordance rates (from 8.8% to 2%) and false-negative rates (from 29.3% to 4%). 4

These conferences should:

• Review all benign biopsies from BI-RADS 4-5 lesions to identify potential discordance 3, 4, 5
• Include radiologists, pathologists, and surgeons to reach consensus on concordance 3, 4, 5
• Document the rationale for concordance or discordance determination 3, 4

Common Pitfalls to Avoid

Never accept benign pathology at face value for highly suspicious imaging findings without confirming concordance. 1 The false-negative rate for discordant cases can be as high as 29.3% without proper multidisciplinary review. 4

Critical errors include:

• Failing to compare biopsy results with the original imaging characteristics before finalizing management 1
• Assuming adequate sampling occurred without reviewing post-biopsy imaging to confirm lesion targeting 2
• Delaying surgical excision when clear discordance exists, as 27.5-36% of discordant cases harbor malignancy 2, 6
• Not obtaining post-biopsy imaging to verify the biopsy site corresponds to the imaging abnormality 2

For indeterminate or borderline cases, err on the side of surgical excision rather than observation, given the substantial malignancy rate in discordant lesions. 2, 6