Atypical Lobular Hyperplasia (ALH)

ALH is generally an incidental finding:
- Without specific defining characteristics on mammography, ultrasound, or MRI
A palpable breast mass which yields ALH at core needle biopsy:
- Is not clinically concordant and should prompt further diagnostic workup with a second biopsy:
  - Either core or excisional
ALH alone confers a 4 to 5 fold increased risk of breast cancer
Risk reducing mastectomy (RRM):
- Can be considered in patients with a lifetime risk of breast cancer ≥ 20% based on history of:
  - ADH / ALH or family history:
    - But this risk must be quantified using a risk assessment tool such as the Gail or Tyrer-Cuzick model
ALH should only be considered for observation:
- When it is diagnosed incidentally and there is radiologic, pathologic, and clinical concordance
Relevant indications for genetic testing include:
- Personal history of breast cancer ≤ 45 years of age
- Triple negative breast cancer ≤ 60 years of age
- A first-degree relative with breast cancer ≤ 50 years of age
- Two or more first- or second-degree relatives with breast cancer at any age
- Patient or relative with bilateral breast cancer
- Male breast cancer in a relative at any age
The Gail Model:
- Should only be used in patients ≥ 35 years of age:
  - May underestimate risk in patients with strong family history or non-Caucasian ethnicity
The Tyrer-Cuzick model:
- May be more appropriate in this setting
References:
- Morrow M, Schnitt SJ, Norton L. Current management of lesions associated with an increased risk of breast cancer. Nat Rev Clin Oncol. 2015; 12: 227-238. National Comprehensive Cancer Network (NCCN) Guidelines (Login Required): Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic, Version 1.2021. Breast Cancer Risk Reduction, Version 1.2020.