Is atypical lobular hyperplasia (ALH) considered a high-risk breast lesion?

Atypical Lobular Hyperplasia as a High-Risk Breast Lesion

Yes, atypical lobular hyperplasia (ALH) is definitively considered a high-risk breast lesion that significantly increases the risk of developing breast cancer, with a lifetime risk approximately 4-5 times that of the general population. 1

Risk Profile of ALH

• ALH is classified as a proliferative lesion with atypia, alongside atypical ductal hyperplasia, lobular carcinoma in situ (LCIS), and flat epithelial atypia 2
• Women with ALH have a continuous risk of approximately 0.5% to 1.0% per year for developing breast cancer 1
• The risk affects both breasts, not just the breast where ALH was identified 1
• ALH behaves similarly to atypical ductal hyperplasia (ADH) in terms of later breast cancer outcomes, with both showing a 2:1 ratio of ipsilateral to contralateral breast cancer development 3

Clinical Implications

Diagnosis and Assessment

• When ALH is diagnosed on core needle biopsy, assessment should include:
  • Extent of ALH (number of terminal ductal units involved)
  • Presence of other high-risk lesions
  • Radiologic-pathologic concordance 1

Management Recommendations

• ALH involving more than 4 terminal ductal units or with radiologic-pathologic discordance requires surgical excision 1
• Limited ALH (≤3 foci) with radiologic-pathologic concordance can safely be managed by imaging surveillance rather than surgical excision 1, 4, 5
• The ipsilateral predominance of breast cancer is marked in the first 5 years after diagnosis, consistent with a precursor phenotype for ALH 3

Surveillance Protocol

• Regular clinical examinations every 6-12 months
• Annual diagnostic mammography
• Consider supplemental screening with breast MRI, especially for women with dense breasts 1
• Surveillance must be bilateral and long-term, as the risk persists for decades 1

Risk Reduction Strategies

• All women with ALH should be informed about chemoprevention options 1
• Recommended chemoprevention options include:
  • Tamoxifen for premenopausal women (reduces invasive breast cancer risk by approximately 46%)
  • Raloxifene for postmenopausal women 1
• A formal individualized education and counseling session can improve chemoprevention acceptance and completion rates 6
• Bilateral risk-reduction mastectomy may be considered in special circumstances (BRCA1/2 mutations, strong family history, patient preference) 1

Common Pitfalls to Avoid

• Overtreatment: Surgical excision is not always necessary for limited ALH (≤3 foci) with radiologic-pathologic concordance 1, 5
• Inadequate follow-up: The risk of breast cancer persists long-term, requiring consistent surveillance for decades 1
• Failure to discuss risk reduction options: Chemoprevention can significantly reduce breast cancer risk but is often underutilized 1, 6
• Treating all atypical lesions the same: Management should be tailored based on extent of ALH and presence of other high-risk factors 1

ALH represents a significant risk factor for future breast cancer development that requires appropriate risk assessment, consideration of surgical excision in specific circumstances, long-term surveillance, and discussion of risk reduction strategies.