Improved reporting methods for atypia and atypical ductal hyperplasia in breast core needle biopsy specimens. Potential for interlaboratory comparisons

Risk of upgrade of atypical ductal hyperplasia after stereotactic breast biopsy: effects of number of foci and complete removal of calcifications

PURPOSE

To determine if patients with fewer than three foci of atypical ductal hyperplasia (ADH) who have all of their calcifications removed after stereotactic 9- or 11-gauge vacuum-assisted breast biopsy (VABB) have a rate of upgrade to malignancy that is sufficiently low to obviate surgical excision.

MATERIALS AND METHODS

An institutional review board-approved, HIPAA-compliant retrospective review of 991 cases of consecutive 9- or 11-gauge stereotactic VABB performed during a 65-month period revealed 147 cases of atypia. One pathologist performed a blinded review of the results of procedures performed to assess for calcifications and confirmed ADH in 101 cases with subsequent surgical excision. Each large duct or terminal duct-lobular unit containing ADH was considered a focus and counted. Postbiopsy mammograms were reviewed to determine whether all calcifications were removed. Upgrade to malignancy was determined from excisional biopsy pathology reports. Upgrade rates as a function of both number of foci and presence or absence of residual calcifications were calculated and compared by using chi(2) tests.

RESULTS

Upgrade to malignancy occurred in 20 (19.8%) of the 101 cases. The upgrade rate was significantly higher in cases of three or more foci of ADH (15 [28%] of 53 cases) than in cases of fewer than three foci (five [10%] of 48 cases) (P = .02). Upgrade rates were similar, regardless of whether all mammographic calcifications were removed (seven [17%] of 41 cases) or all were not removed (nine [20%] of 45 cases) (P = .77). Upgrade occurred in two (12%) of 17 cases in which there were fewer than three ADH foci and all calcifications were removed.

CONCLUSION

The upgrade rate is significantly higher when ADH involves at least three foci. Surgical excision is recommended even when ADH involves fewer than three foci and all mammographic calcifications have been removed, because the upgrade rate is 12%.

Lésions mammaires impalpables et macrobiopsies stéréotaxiques avec le Mammotome® 11 G : faut-il opérer après diagnostic d’hyperplasie canalaire atypique ?

Atypical ductal hyperplasia (ADH) of the breast is a difficult histologic diagnosis. It is usually found, but not always, on clusters of microcalcifications. The subsequent risk of breast carcinoma is 4 to 5 times more important and the carcinoma can arise in the same breast or in the contralateral breast. Diagnosis can be establish on core needle biopsy with Mammotome 11G. The risk of under-estimation (ductal carcinoma in situ or invasive carcinoma) is about 20%. This risk is drastically decreased if the target (the calcifications) is completely removed by the Mammotome. This study includes 62 cases of ADH found on 633 calcifications biopsied by Mammotome 11G. In 31 cases, surgery was performed and ADH was confirmed in 25 cases (6 cases was under-estimated). In the other 31 cases, all calcifications were removed, there was no other risk factor and follow-up was suggested. Like after surgery, yearly bilateral mammography during about 20 years is recommended. In this last group, there was no false-negative result, median follow-up: 35,5 months (22-62).

Atypical ductal hyperplasia and atypia of uncertain significance in core biopsies from mammographically detected lesions: correlation with excision diagnosis

AIMS

To assess: (1) the prevalence of reporting of atypical ductal hyperplasia (ADH) and intraductal atypia of uncertain significance (AUS) in a series of core biopsies from mammographically detected lesions, (2) the proportion of cases where excision revealed breast carcinoma, and (3) whether any diagnoses should be revised on review.

METHODS

Breast core biopsy reports from the Sir Charles Gairdner Hospital Breast Assessment Centre for the years 1999-2000 were retrieved. Slides from cases reported as ADH or AUS were reviewed as well as slides from the excision biopsies.

RESULTS

There were 1048 core biopsies from 911 women. Breast carcinoma was diagnosed in 197 samples (18.8%) including 88 with invasive carcinoma (8.4%), 109 with ductal carcinoma in situ (DCIS) (10.4%). Three biopsies (0.3%) 'suspicious' of invasive carcinoma proved to be so. Of 52 samples (5.0%) with a diagnosis of ADH or AUS, 46 were excised, showing seven invasive carcinomas, 15 DCIS, 11 ADH, two lobular carcinoma in situ (LCIS), nine fibrocystic change (FCC), one mucocoele-like lesion and one fibroadenoma. The 22 malignancies represented 47.8% of the excised lesions. On review, seven of the 52 original core diagnoses were downgraded to benign hyperplasia. Five underwent excision, revealing two FCC, one complex sclerosing lesion, and two incidental lesions unrelated to the mammographic abnormality, including a microscopic tubular carcinoma and a focus of LCIS. In one case reviewed as unsatisfactory, excision showed invasive carcinoma. Lesions of particular interest included a case of high-grade DCIS with local regression in the core biopsy (so-called 'bumt out DCIS'), and one case diagnosed on excision as micropapillary ADH, where the review diagnosis was micropapillary DCIS.

CONCLUSIONS

ADH and AUS were reported in 5.0% of biopsies. There was a high rate of carcinoma (47.8%) in subsequent excisions. Very few diagnoses were revised on review. Current protocols for excision of lesions with a 14-gauge core biopsy diagnosis of ADH/AUS appear justified. Literature review suggests that vacuum-assisted core sampling with 11-gauge needles will not remove the need for excision. Further study of local regression of DCIS and micropapillary lesions will be worthwhile.

Atypical ductal hyperplasia: can some lesions be defined as probably benign after stereotactic 11-gauge vacuum-assisted biopsy, eliminating the recommendation for surgical excision?

PURPOSE

To determine if a subset of atypical ductal hyperplasia (ADH) lesions diagnosed at 11-gauge, directional, vacuum-assisted, prone, stereotactic biopsy fit the "probably benign" definition of a less than 2% chance of being carcinoma at subsequent surgical excision.

MATERIALS AND METHODS

Clinical, mammographic, and stereotactic biopsy features in 104 consecutive nonpalpable ADH lesions were correlated with the presence of carcinoma at lumpectomy. The results were analyzed with chi(2) statistic, with P <.05 indicative of significant difference.

RESULTS

Surgical excision revealed carcinoma in 22 (21%) of 104 ADH lesions. The lowest incidences of carcinoma (each P <.02) were 16% (15 of 92) in patients with no personal history of breast carcinoma, 13% (nine of 67) when maximum lesion diameter was less than 10 mm, and 8% (three of 36) when 100% of the mammographic lesion was removed at stereotactic biopsy.

CONCLUSION

No clinical, mammographic, or biopsy features alone or in combination could be used to define a substantial subset of probably benign lesions with a less than 2% chance of carcinoma at lumpectomy.