Atypical ductal hyperplasia (ADH) is a pathologic finding in breast tissue. Atypical ductal hyperplasia is usually identified incidentally on specimens obtained by needle biopsy prompted by abnormal findings on mammography. Atypical ductal hyperplasia correlates with an increased risk of breast cancer and therefore classified as a "high risk" lesion but is not a "precursor" lesion - the distinction being the breast cancer associated with ADH can occur anywhere in the breasts and not only in the area of the ADH. Because most ADH is found incidentally, the actual incidence is unknown. It is known, once identified, to increase the risk of breast cancer approximately fivefold.[1]
The etiology of atypical ductal hyperplasia is unknown; however, ADH is more prevalent in patients with a strong family history of breast cancer.[2] Hoogerbrugge et al. found that nearly 50% of women undergoing prophylactic mastectomies due to high family risk of breast cancer uncovered high-risk lesions, 39% of which were ADH; this suggests that there is a hereditary component involved, which requires further study.
Additionally, a study from 2009 demonstrated that rates of ADH have declined with the loss of favor of post-menopausal hormonal therapies, suggesting this also may have been a contributing factor.[3]
Atypical ductal hyperplasia, due to its lack of imaging findings, is, by definition, an incidental pathology finding. Most frequently, this is found on core needle biopsy; however, it can also be discovered on excisional biopsies, breast oncologic surgeries, cosmetic breast reductions, or any other breast surgery resulting in submitting breast tissue to pathology. The prevalence of atypical ductal hyperplasia in biopsies has been in the 3.5 to 5% range and most frequently found on core needle biopsy.[4]
Rates of ADH in a large study from 2009 reviewing nearly 31,000 biopsies demonstrated initially increasing rate of diagnosis with the increase in breast cancer awareness, screening mammographies, prophylactic mastectomies, and use of post-menopausal hormonal therapy - resulting in peak diagnosis of ADH in 1999 (5.5 cases per 10,000 mamograms). Since the loss of favor of post-menopausal hormonal therapy, however, there has been a slight decrease in the diagnosis of ADH over time.[3]
Typical patients are females in their fifth to sixth decade of life, as this is the population most likely to be undergoing breast biopsies. Males are also susceptible to atypical ductal hyperplasia, although diagnosis is less common. One Dutch study analyzing over 5,000 cases of excised breast tissue for gynecomastia in males found a prevalence of 0.4% of atypical ductal hyperplasia.[5]
Atypical ductal hyperplasias of the breast are proliferative lesions of the breast that have some, but not all, of the architectural and cytologic features of low-grade ductal carcinoma in situ (DCIS). Specifically, you will find an abnormal accumulation in the ducts of relatively uniform epithelial cells notable for monomorphic round nuclei, regular cell placement, and round regular spaces in at least part of the specimen. What sets it apart from DCIS, however, is that these cells make up only a portion of the specimen.[4][1][6]
Atypical ductal hyperplasia is most often found after biopsy in the setting of calcifications found on mammography or imaging. ADH can also be found incidentally on other breast tissue that is sent to pathology for any number of reasons, including oncologic resections, plastic surgery resections, excisional biopsies, etc. There are no physical findings on the exam, such as a lump, breast discoloration, or breast distortion grossly.
It is important to know the type of specimen in which the ADH is identified because the lesion's management depends on it.
If atypical ductal hyperplasia is found on core needle biopsy, additional tissue is necessary by excisional biopsy. A wire or seed localization technique should be used at the time of the core biopsy to later identify the area potentially requiring excision. The reason for re-excision is that with a more extensive tissue specimen, there is a chance the lesion will be upgraded to carcinoma in situ or invasive carcinoma. Studies suggest that 22 to 65% of ADH found on core needle biopsies were upgraded to carcinoma after subsequent excisional biopsy.[7][8] Most upgrades are to DCIS; however, IDC is also sometimes found.
If, however, ADH alone is diagnosed on an excisional biopsy, no additional surgery is required, even if there are positive margins because ADH is a high-risk lesion, but it is not a pre-cancerous or cancerous lesion.[1][7][9]
Once identifying atypical ductal hyperplasia as the diagnosis and ruling out breast carcinoma, it is essential to address risk reduction strategies.
One such measure is treating these patients with tamoxifen, as the vast majority of lesions are ER+. In the National Surgical Adjuvant Breast and Bowel Project (NSABP) P-1 trial, tamoxifen conferred a risk reduction of 86% in women with ADH.[10] Therefore, we recommend the discussion of tamoxifen in patients diagnosed with ADH. Tamoxifen is known to increase the risk of endometrial cancer, stroke, DVT, and PE - particularly in patients over the age of 50. Therefore the risk-benefit discussion starting tamoxifen would need to include consideration of these risks and the decision to begin tamoxifen be patient dependant.
Additionally, it is important to increase surveillance and awareness in the patient.[11][6]
If a core biopsy identifies atypical ductal hyperplasia, it is important to take a larger excisional biopsy to ensure a large enough specimen to rule out carcinoma of the breast. It is also important to note that on biopsy, low-grade DCIS and ADH share many morphologic similarities. Therefore the pathology specimen at hand should be carefully examined to rule out DCIS.[1]
Atypical ductal hyperplasia has a history of surgical overtreatment. If diagnosed on core needle biopsy, a more extensive excisional biopsy is required to rule out breast carcinoma.[12] If, however, ADH and only ADH is found on excisional biopsy, the patient is surgically complete; this includes cases where margins are positive. As ADH is not cancer, there is no need for node sampling nor any role for mastectomy.
There is no role at this time for radiation therapy in a patient diagnosed only with atypical ductal hyperplasia.
Complications of atypical ductal hyperplasia result from both over and undertreating the diagnosis. There is a risk of missing a breast carcinoma with undertreatment of ADH and not proceeding with additional tissue sampling.[13][12] There is also a risk of overtreating ADH with aggressive surgeries (e.g., mastectomy or excessively large biopsies) in the setting of no malignancy.[11] There is toxicity risk from chemotherapy agents if ADH is misrecognized as a cancerous or precancerous lesion rather than a high-risk lesion. As discussed above, there are known and well-established complications as a result of tamoxifen that should also merit consideration before starting treatment.
Patients should receive education on the meaning of the diagnosis as well as the actual risk conferred by the diagnosis of atypical ductal hyperplasia. Patients diagnosed with ADH should be followed closely by a clinician, given a higher risk of breast carcinoma in the future.[11] Additionally, standard cancer risk-reducing guidelines are recommended, such as normalizing BMI and smoking cessation.
Atypical ductal hyperplasia is a pathology finding, usually found incidentally on biopsy of the breast. The diagnosis by itself is not a precancerous or cancerous lesion. It is, however, a high-risk lesion, indicating the presence of ADH on pathology flags the patient as one who is fivefold more likely to develop breast carcinoma - in any area of the breasts - in the future. For this reason, the nuance of the cancer risk of the finding of ADH on pathology is more challenging to communicate with the patient.
Regardless of lesion excision, there is still an increased risk to the patient of developing breast carcinoma that will require continued monitoring and screening. The patient may also benefit from tamoxifen therapy as a breast cancer prevention agent, depending on if ER+ and if the patient is suitable for tamoxifen given the side effect profile. (Level I)
It is also crucial that surgeons know the appropriate surgical management of this finding. ADH on core needle biopsy will require needle or seed localized excisional biopsy to rule out nearby breast carcinoma. However, if ADH is found on excisional biopsy to be ADH only - even if margins are positive - the patient is surgically complete. [Level 2]
[1] | Kader T,Hill P,Rakha EA,Campbell IG,Gorringe KL, Atypical ductal hyperplasia: update on diagnosis, management, and molecular landscape. Breast cancer research : BCR. 2018 May 2; [PubMed PMID: 29720211] |
[2] | Hoogerbrugge N,Bult P,de Widt-Levert LM,Beex LV,Kiemeney LA,Ligtenberg MJ,Massuger LF,Boetes C,Manders P,Brunner HG, High prevalence of premalignant lesions in prophylactically removed breasts from women at hereditary risk for breast cancer. Journal of clinical oncology : official journal of the American Society of Clinical Oncology. 2003 Jan 1; [PubMed PMID: 12506168] |
[3] | Menes TS,Kerlikowske K,Jaffer S,Seger D,Miglioretti DL, Rates of atypical ductal hyperplasia have declined with less use of postmenopausal hormone treatment: findings from the Breast Cancer Surveillance Consortium. Cancer epidemiology, biomarkers [PubMed PMID: 19900937] |
[4] | Hartmann LC,Degnim AC,Santen RJ,Dupont WD,Ghosh K, Atypical hyperplasia of the breast--risk assessment and management options. The New England journal of medicine. 2015 Jan 1; [PubMed PMID: 25551530] |
[5] | Lapid O,Jolink F,Meijer SL, Pathological findings in gynecomastia: analysis of 5113 breasts. Annals of plastic surgery. 2015 Feb; [PubMed PMID: 23788148] |
[6] | Peña A,Shah SS,Fazzio RT,Hoskin TL,Brahmbhatt RD,Hieken TJ,Jakub JW,Boughey JC,Visscher DW,Degnim AC, Multivariate model to identify women at low risk of cancer upgrade after a core needle biopsy diagnosis of atypical ductal hyperplasia. Breast cancer research and treatment. 2017 Jul [PubMed PMID: 28474262] |
[7] | Rageth CJ,O'Flynn EA,Comstock C,Kurtz C,Kubik R,Madjar H,Lepori D,Kampmann G,Mundinger A,Baege A,Decker T,Hosch S,Tausch C,Delaloye JF,Morris E,Varga Z, First International Consensus Conference on lesions of uncertain malignant potential in the breast (B3 lesions). Breast cancer research and treatment. 2016 Sep; [PubMed PMID: 27522516] |
[8] | Allen A,Cauthen A,Dale P,Jean-Louis C,Lord A,Smith B, Evaluating the frequency of upgrade to malignancy following surgical excision of high-risk breast lesions and ductal carcinoma in situ identified by core needle biopsy. The breast journal. 2019 Jan [PubMed PMID: 30461129] |
[9] | Rageth CJ,O'Flynn EAM,Pinker K,Kubik-Huch RA,Mundinger A,Decker T,Tausch C,Dammann F,Baltzer PA,Fallenberg EM,Foschini MP,Dellas S,Knauer M,Malhaire C,Sonnenschein M,Boos A,Morris E,Varga Z, Second International Consensus Conference on lesions of uncertain malignant potential in the breast (B3 lesions). Breast cancer research and treatment. 2019 Apr [PubMed PMID: 30506111] |
[10] | Fisher B,Costantino JP,Wickerham DL,Cecchini RS,Cronin WM,Robidoux A,Bevers TB,Kavanah MT,Atkins JN,Margolese RG,Runowicz CD,James JM,Ford LG,Wolmark N, Tamoxifen for the prevention of breast cancer: current status of the National Surgical Adjuvant Breast and Bowel Project P-1 study. Journal of the National Cancer Institute. 2005 Nov 16; [PubMed PMID: 16288118] |
[11] | [PubMed PMID: 29099502] |
[12] | [PubMed PMID: 30591993] |
[13] | [PubMed PMID: 29146271] |