Atypical Ductal Hyperplasia and Papillomas: A Comparison of Ultrasound Guided Breast Biopsy and Stereotactic Guided Breast Biopsy Breast Cancer is the most common cancer diagnosed in women in the United States, excluding skin cancer. The American Cancer Society (ACS) has reported that the lifetime probability of a woman developing breast cancer is 1 in 8. The good news is that mortality has decreased by 34% since 1990 [1]. The decline in mortality has been attributed to improvements in treatment and early detection. An important tool in the early identification of breast cancer is minimally invasive needle core breast biopsy. Core needle breast biopsy can be performed under stereotactic or ultrasound guidance. These procedures are highly accurate for the diagnosis of breast carcinoma. Findings can be categorized as malignant, benign, or high risk. High risk lesions include atypical ductal hyperplasia (ADH), lobular carcinoma in situ (LCIS), papillomas, radial scars, and fibroepithelial lesions. High risk lesions either confer increased risk to the patient for development of carcinoma and/or are associated with the presence of carcinoma on subsequent excisional biopsy. There is general consensus that ADH has a sufficiently high risk of adjacent malignancy (approximately 18% risk of DCIS or IDC) that excision is warranted. The data is not as clear for other lesions. Recent literature on papillomas reveals a range of 1% to 18% upgrade to malignancy. In addition, there are conflicting recommendations for managing patients who are found to have papillomas. Some authors recommend imaging follow up and others recommend surgical excision [2]. In order to assess current management of high risk lesions diagnosed at the Baptist Breast Center (BBC) Polly Hansen, M.D., Radiologist at the BBC, performed a retrospective study of biopsies performed during 2012 to compare the upgrade rates for ultrasound (US)- guided versus stereotactic guided biopsies with high risk pathology on core biopsy. 1
OBJECTIVE: The purpose of the study is to determine our upgrade rates for Atypical Ductal Hyperplasia (ADH) and papillomas identified by core needle biopsy with ultrasound or stereotactic methods. METHODS: 1 ST STUDY: STEREOTACTIC GUIDED Two- hundred forty eight (248) stereotactic guided breast biopsies were reviewed. Sixty (24.2%) cancers were detected and one- hundred forty- nine (60%) benign lesions identified. Thirty- nine (15.7%) of the procedures were recommended to undergo repeat/excisional biopsy or surgical consult due to high- risk pathology. Thirty (30) of the cases were described as cellular atypia, including twenty- two (22) cases of ADH. In addition, there were five (5) cases of papilloma. RESULTS: Twenty (20) of the twenty- two (22) cases of ADH were excised and four (4) patients (18%) were found to have DCIS. No cases of invasive ductal carcinoma (IDC) were found. Two (2) cases of ADH were not excised. Follow- up showed that one (1) case remained stable at one year all calcifications had been removed. The other case of ADH has no follow up despite phone calls, two letters to the patient and one letter to doctor. All five of the papilloma cases identified at stereotactic biopsy were excised and confirmed as benign, resulting in a 0% upgrade rate. The stereotactic results are likely related to nearly complete sampling of most calcifications and the use of a 7 or 11g needle size typically used for large core vacuum assisted biopsy. The 18% upgrade rate for ADH is in line with published results. The papillomas biopsied under stereotactic guidance all presented as small clusters of calcifications which were completely removed at the time of biopsy. This suggests that these were small intraductal papillomas which were thoroughly sampled. 2
2 nd STUDY: ULTRASOUND GUIDED Four- hundred sixty- nine (469) US guided breast biopsies were reviewed. One- hundred forty- seven (31.3%) cancers were detected. Two- hundred seventy- five (58.6%) benign lesions identified. Forty- seven (10%) of the procedures were recommended to undergo excisional biopsy or surgical consult due to high- risk (46) or discordant (1) results. Four (4) of the 47 were categorized as ADH at biopsy with two (2) subsequently upgraded to DCIS/IDC. The other two ADH cases were benign at excision. The one discordant lesion was excised with benign histology. Additionally, twenty- nine (29) of the forty- seven (47) cases or (62%) were categorized as papillomas. Eighteen (18) were benign at excision, and six (6) cancers were identified. Five (5) of the cases were changed to follow- up by referring physician. These patients have all received reminder phone calls at six months along with reminder letters but had not returned for follow up by the time of this review. letter. In addition, their referring physicians were reminded with a RESULTS: The results showed a 50% upgrade rate for the ADH diagnosed with the ultrasound- guided core needle biopsy. ADH does not present as a mass. These core results could be considered discordant with the imaging findings, but since ADH is high- risk and usually excised, these results were not categorized as such by the radiologist. All ADH lesions were appropriately recommended for excision. For the papillomas diagnosed by ultrasound guided core needle biopsy, there was a 21% upgrade rate to malignancy. This is higher than expected. There are several possible explanations for this. Our radiologists predominantly use fourteen (14) gauge core biopsy needles for ultrasound guided procedures. The smaller needle results in an inherent sampling error as the whole lesion is not removed. Papillomas are heterogeneous lesions, so the larger the lesion is with respect to the needle, the more significant this effect will be. Also, the lesions biopsied under ultrasound guidance were significantly larger than the papillomas biopsied under stereotactic guidance. 3
CONCLUSION: This study revealed a 21% (6 out of 29) upgrade rate for US guided core needle biopsy for papillomas. As a comparison, stereotactic core needle biopsy for papillomas produced a 0% (0 out of 5) upgrade rate. This information is important for the breast imager to keep in mind when performing the radiologic pathologic correlation following the biopsy. The radiologist needs to adequately convey to the referring physician the probability that the lesion will be upgraded to a malignancy. For ultrasound detected lesions which are larger and have suspicious ultrasound characteristics, greater emphasis should be placed on the recommendation for subsequent excision. Close communication with the pathologist is also necessary. The unexpectedly high upgrade of ADH to malignancy on ultrasound was an important finding. As previously noted, ADH should probably be handled as a discordant biopsy result by the radiologist, unless there is some other pathologic lesion to explain the ultrasound finding, in which case ADH would be an incidental high risk lesion. In either case, the lesion should be excised, due to the high rate of associated/adjacent malignancy. Limitations of the study include sample size, retrospective review and limited details about this patient group. RECOMMENDATIONS: Surgeons should be made aware of the study and the results. The radiologists and pathologists should be encouraged to communicate with each other regarding the level of concern for papilloma upgrades based on imaging and histologic findings, and include the management recommendations in both reports. Jill Uecker, M.D., Pathologist at the BBC will analyze the papilloma data and pathologists reports for a companion study. Careful radiologic- pathologic correlation, physician education and improved communication are key elements which should be stressed throughout the Baptist Breast Network. 4
References 1. American Cancer Society. Breast Cancer Facts & Figures 2011-2012. Atlanta: American Cancer Society, Inc. 2. Yu- Mee Sohn, MD, PhD & So Hyun Park, MD. Comparison of Sonographically Guided Core Needle Biopsy and Excision in Breast Papilloma. J Ultrasound Med 2013; 32:303-311. 5