Management of Atypical Ductal Hyperplasia on Core Needle Biopsy
When atypical ductal hyperplasia (ADH) is diagnosed on core needle biopsy, surgical excisional biopsy is mandatory due to a 15-42% risk of upgrade to ductal carcinoma in situ (DCIS) or invasive cancer. 1
Why Surgical Excision is Required
The core needle biopsy provides only a limited tissue sample that frequently misses concurrent malignancy elsewhere in the lesion. 1, 2 The NCCN explicitly states that active surveillance for ADH remains investigational and is not endorsed—surgical excision continues to be the standard of care. 1
Upgrade Rates from Research Studies
- Pooled data from 39 studies (3,125 excision procedures) shows a median upgrade rate of 25% (range 4-54%) when ADH on core biopsy undergoes surgical excision. 3
- Individual studies report upgrade rates of 33% 4 to 41.6% 3 to DCIS or invasive carcinoma.
- Patients presenting with a palpable breast mass or suspicious mammograms (BIRADS ≥4) have significantly higher upgrade rates. 3
Surgical Technique and Specimen Handling
Specimen radiography must be performed to confirm retrieval of the microcalcifications that prompted the biopsy. 2 The specimen should be oriented with sutures or markers (superior, medial, lateral) for the pathologist, and margins should be marked with India ink to determine tumor presence at excision margins. 2
Critical pitfall to avoid: Frozen section examination should never be performed for microcalcifications, as distinguishing ADH from DCIS may be impossible on frozen tissue, and small foci of microinvasion can be lost or rendered uninterpretable by freezing artifact. 5, 2
Post-Excision Risk Reduction Therapy
After surgical excision confirms ADH without upgrade to cancer, tamoxifen 20 mg daily for 5 years should be strongly considered, as it provides a 75% reduction in the occurrence of invasive breast cancer in women with ADH (NCCN Category 1 evidence—the highest level). 1, 6
Risk Context
- ADH confers a 4- to 5-fold increased risk of developing invasive breast cancer. 6, 2
- The continuous annual breast cancer risk is approximately 0.5-1.0%, with cumulative 10-year risk 2.6 times higher than women without ADH. 6, 2
- Risk doubles if there is an associated family history of breast cancer. 6
- Risk remains elevated in both breasts for decades, not just the ipsilateral breast. 6
Tamoxifen Monitoring Requirements
Patients receiving tamoxifen require monitoring for:
- Vasomotor symptoms, muscle spasms, and gynecologic symptoms. 6
- Thromboembolic symptoms (deep vein thrombosis risk). 6
- Baseline and periodic gynecologic evaluation due to endometrial cancer risk. 6
- Stroke risk assessment. 6
Lifelong Surveillance Protocol
All women with ADH require lifelong surveillance regardless of whether they take tamoxifen, including: 1, 6, 2
- History and physical examination every 6-12 months for 5 years, then annually
- Annual diagnostic mammography (not just screening mammography)
- More intensive screening should be considered in patients with ADH and a family history of breast cancer in a first-degree relative 1
The ipsilateral breast is at especially high risk for breast cancer in the first 5 years after atypia diagnosis, with risk remaining elevated in both breasts long-term. 7 Both ADH and ALH show a 2:1 ratio of ipsilateral to contralateral breast cancer, with the ipsilateral predominance most marked in the first 5 years. 7
Characteristics of Subsequent Breast Cancers
When breast cancer develops after ADH, 69% are moderate or high grade, 25% are node-positive at diagnosis, and the majority are invasive ductal cancers rather than low-grade DCIS. 7 This contradicts the common assumption that ADH only leads to low-grade cancers and underscores the importance of aggressive surveillance.