Atypical ductal hyperplasia in breast core needle biopsies. Correlation of size of the lesion, complete removal of the lesion, and the incidence of carcinoma in follow-up biopsies.

We reviewed the results of all breast core needle biopsies with a diagnosis of atypical ductal hyperplasia (ADH) or atypia not otherwise specified and subsequent excisional biopsies for a 50-month period and correlated the results. Of 3,026 biopsies, 216 were diagnosed as ADH or atypia not otherwise specified, and subsequent resection was available for 105. After review, 95 qualified as ADH. Subsequent resection showed ductal carcinoma in situ (DCIS) in 13 excisions, ADH in 31, lobular carcinoma in situ in 6, and benign proliferative lesions in the remaining 45. In none of the 8 biopsies in which DCIS was found and radiographs were available for review was the radiographic lesion entirely removed. For comparison, the incidence of carcinoma in resections done for a diagnosis of DCIS, low or intermediate grade (solid, cribriform, or micropapillary type), on core needle biopsy was significantly greater (8 of 10 cases). However, the size of the lesions diagnosed as carcinoma also was significantly greater than that of the lesions diagnosed as ADH, and in none of the 8 biopsies with DCIS at excision was the lesion entirely removed at the time of biopsy. The incidence of carcinoma in excisional biopsies done for a diagnosis of ADH in core needle biopsies in our institution is relatively low, while the incidence of ADH is relatively high. Possible reasons for this include total removal of small lesions at the time of biopsy and use of the diagnostic term ADH for lesions that are not associated with coexistent DCIS.     

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.     

Nuclear morphometry in columnar cell lesions of the breast: is it useful?

AIMS: To evaluate the nuclear morphometric features of breast columnar cell lesions (CCLs) observed on mammotome core biopsies, to determine if there are significant measurable differences between those with atypia and those without. Correlation with follow-up open excision specimens was made. METHODS: Mammotome core biopsies performed on patients that contained CCLs were derived from the departmental case files. Histological material was reviewed and foci of CCLs demarcated for nuclear morphometric assessment, which was accomplished using an imaging system. Nuclear parameters studied were nuclear area and perimeter, circularity factor and feret's diameter. Statistical analysis used the GraphPad Prism software, with p<0.05 indicating significance. RESULTS: On examination of core biopsies of 40 patients with CCLs, 8 lesions were benign, 4 showed atypical lobular hyperplasia, 8 showed CCLs with nuclear atypia, 19 disclosed atypical ductal hyperplasia (ADH) and 1 showed ductal carcinoma in situ (DCIS). The nuclear area, perimeter and feret's diameter of CCLs with atypia were significantly greater than those without (p = 0.04, 0.03 and 0.019, respectively), whereas no difference was observed in the circularity factor. Follow-up open excision biopsy specimens in 24 patients showed upgrading to DCIS in 40% of cases diagnosed initially with ADH on core biopsy compared with 20% of CCLs with atypia. CONCLUSIONS: Nuclear morphometry in CCLs confirms nuclear size as the key parameter in the assessment of nuclear atypia. Whether it can be potentially used as an adjunctive tool depends on the establishment of appropriate cut-offs.     

Mucin extravasation in breast core biopsies – clinical significance and outcome correlation

Aims:  To document the spectrum of lesions associated with mucin extravasation (ME) in breast core biopsy specimens, and to correlate with open surgical excisions.
Methods and results:  Thirty-nine lesions in 37 women with ME on core biopsies constituted the study group. Fibrocystic change (FC), atypical ductal hyperplasia (ADH) and ductal carcinoma in situ (DCIS) were found in 21 (53.8%), 13 (33.3%) and four (10.3%) core biopsy specimens, respectively, with one (2.6%) consisting only of mucin pools. Except for the latter, all disclosed mucocoele-like lesions (MLL) accompanying ME. Columnar cell lesions (CCL) were frequently observed (84.6%). On open biopsy, three cases underdiagnosed on core biopsy included FC that later disclosed ADH; one ADH lesion on core later upgraded to DCIS; and a case of mucin pools that revealed mucinous carcinoma on excision. The extent of CCL on core biopsy appeared to predict sinister lesions on open excision. For calcified lesions that were completely removed on core biopsy, there were no malignant lesions discovered on open excision that had not already been diagnosed preoperatively.
Conclusions:  ME and MLL on core biopsy warrant close radiological–pathological correlation. When the entire radiological abnormality has been removed with large core mammotome biopsy specimens, surgery may potentially be avoided in histologically benign lesions, although such an approach requires further validation.     

Clinicopathologic analysis of breast lesions associated with multiple papillomas

We performed a retrospective clinicopathologic study of 28 patients with breast lesions characterized by the presence of multiple (at least 5) papillomas (MPs) in at least 2 nonconsecutive blocks. All histologic sections were assessed for the presence of coexisting fibrocystic lesions, including atypical hyperplasia (atypical ductal hyperplasia [ADH] or atypical lobular hyperplasia [ALH]), lobular carcinoma in situ (LCIS), and papillary atypia (defined as nuclear hyperchromatism, stratification, and architectural complexity of a lesser degree than in papillary carcinoma). All of the lesions were compared with a set of cases in which ductal carcinoma in situ (DCIS) (n = 20) or invasive carcinoma (INV)(n = 13) was accompanied by MPs. The MP cases had a characteristic morphologic appearance, typically presenting as a mass comprising multiple adjacent ducts filled by papillomas, accompanied by dense fibrosis and intermingled with various proliferative fibrocystic lesions, particularly florid adenosis. Atypical hyperplasia was a frequent finding (in 12 of 28 cases; 43%), particularly in cases with atypical papillomas (7 of 11; 63.6%). Although contralateral lesions occurred in 4 of 28 patients (14.2%; 3 MPs and 1 INV), only 1 patient (4%) has developed ipsilateral breast carcinoma (mean follow-up, 47 months). DCIS associated with MP was typically low grade (17 of 20; 85%) and arose from areas within or immediately adjacent to preexisting benign lesions. None has recurred (mean follow-up, 41 months), although 1 patient has contralateral MP and 3 patients (23%) have developed carcinomas in the opposite breast. INVs developing in a background of (ipsilateral) MPs were mostly small (8 of 11 <2.0 cm), node negative (7 of 10), and estrogen receptor (ER) positive (8 of 8). Only 1 of 13 patients (8%) has died from disease (mean follow-up, 59 months), but 5 (38%) have developed contralateral breast lesions (including 1 MP, 1 MP-DCIS, 1 DCIS, 1 LCIS, and 1 INV). We conclude that the frequent associations with ADH, ALH/LCIS, malignant lesions, and bilaterality imply that MP may represent a marker of constitutionally increased breast cancer risk. Because carcinomas arose within or close to areas involved by preexisting benign MP lesions, it may also be appropriate to excise segments of tissue involved by MP, particularly cases with atypia, and closely monitor for contralateral disease.     

Atypical ductal hyperplasia and ductal carcinoma in situ of the breast associated with perineural invasion

Perineural invasion is a histologic feature usually diagnostic of invasion in malignancies. In the breast, however, it has been associated with benign lesions such as sclerosing adenosis (SA), complex sclerosing lesion/radial scar (CSL/RS), and ductal carcinoma in situ (DCIS). This article describes perineural invasion associated with atypical ductal hyperplasia (ADH), florid hyperplasia without atypia (FH), and DCIS. All cases with a diagnosis of perineural invasion were selected from a series of 10,000 breast consult cases. Invasive mammary carcinomas were excluded. Fourteen cases of perineural invasion were found and associated with the following diagnoses: ADH (5), DCIS (3), FH (5), and ductal adenoma (1). Nine cases developed in CSL/RS, 4 cases in SA, and 1 case in a previous biopsy site of ductal adenoma; lesions were all less than 3 mm. The glands involving nerves showed cytologic and architectural features of the adjacent ADH, DCIS, and FH. Immunostaining for protein gene product (PGP) 9.5 marked nerves, and smooth muscle actin antibody highlighted the myoepithelial cells around glands. Perineural invasion seen in association with DCIS and ADH, in a background of CSL/RS and SA, may pose difficulty in diagnosis, especially in small biopsy specimens. It should be assessed with care to avoid misinterpretation as invasive mammary carcinoma.     

Practical problems in breast screening. Columnar cell lesions including flat epithelial atypia and lobular neoplasia

Columnar cell lesions (CCL) and lobular neoplasia (LN) are encountered with increasing frequency in breast screening biopsies. CCLs are frequently associated with microcalcifications, whereas LN is an incidental finding in most cases. Flat epithelia atypia (FEA) the atypical variant of CLL, LN and atypical ductal hyperplasia (ADH) are frequently associated lesions. Molecular genetic studies of CCL, ductal carcinoma in situ (DCIS) and low grade invasive carcinomas revealed similar chromosomal alterations supporting the assumption that CCLs are neoplastic proliferations. The frequent association of FEA together with well differentiated invasive carcinomas provides further evidence of this concept. There is no internationally accepted classification of CCLs at present. CDH1-gene mutations are the cardinal feature of LN and invasive lobular carcinoma. In immunohistochemically CDH1-positive cases, alternative genetic alterations of the CDH1 pathway can lead to functional loss of CDH1. In our opinion morphologically and immunohistochemically hybrid lesions may represent this group of lobular lesions. Recent follow-up data suggest a higher rate of ipsilateral carcinomas in patients with previously diagnosed LN. It is currently an open question whether FEA and LN are members of a common family of intralobular proliferations, which are non-obligatory precursors of a low nuclear grade breast neoplasia family.     

PATHOLOGICAL AND BIOLOGICAL CHARACTERISTICS OF INTERVAL BREAST CANCER

INTRODUCTION: Protocols for excision of mammographically detected lesions following core biopsy include all diagnoses of atypical ductal hyperplasia (ADH) or intraductal atypia of uncertain significance (AUS). The aims of this study were to look at: i) the prevalence of reporting ADH and AUS, ii) the proportion of cases where excision revealed breast carcinoma, iii) whether any cases could be downgraded to hyperplasia on review.
METHODS: Breast core biopsy reports from the SCGH Breast Centre for the years 1999–2000 were retrieved. The results of excision biopsy were obtained and slides reviewed.
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 (10.4%) and 3 samples (2.9%) suspicious of invasive carcinoma. The suspicious cases all proved to be invasive carcinomas. There were 53 samples (5.1%) with a diagnosis of ADH or AUS. 46 were excised, showing 7 invasive carcinomas 15 DCIS, 11 ADH, 2 lobular carcinoma in situ (LCIS), 1 mucocoele-like lesion, 1 fibroadenoma and 9 fibrocystic change (FCC). The 22 malignancies represented 47.8% of the excised lesions. At review, 8 of the 53 original diagnoses were downgraded to benign hyperplasia; 5 underwent excision; 2 showed 'incidental' invasive carcinomas, 1 'incidental' LCIS, 1 ADH and 1 FCC.
CONCLUSIONS: There was a low prevalence of reporting of ADH and AUS in core biopsies (5.1%) and a high rate of carcinoma (47.8%) in subsequent excision biopsies. Very few diagnoses of ADH/AUS were downgraded at review. Current protocols for excision of lesions with a core biopsy diagnosis of ADH/AUS appear to be justified.     

Significance of flat epithelial atypia on mammotome core needle biopsy: Should it be excised?

The aim of this study was to determine the morphologic types, associations, and significance of flat epithelial atypia (FEA) with or without atypical ductal hyperplasia (ADH) in mammotome core needle biopsies. We evaluated the correlation of FEA in core biopsies with follow-up excision biopsies to predict the likelihood of upgrade to carcinoma. We also investigated the utility of Ki-67 in predicting which lesions were associated with carcinoma in the excisional biopsies. Core biopsies with a diagnosis of atypia were categorized as pure FEA, pure ADH, or both. The following parameters were recorded: indication for core biopsies, presence of microcalcifications, inflammation, and stromal changes. A total of 60 core biopsies from 56 patients were studied. Pure ADH, pure FEA, and concomitant FEA and ADH were seen in 13%, 23%, and 64% of core biopsies, respectively. The most common architectural pattern of FEA resembled blunt duct adenosis (52%), followed by cystically dilated ducts with secretions (38%) and apocrine features (10%). Chronic inflammation and stromal changes were noted in 29% and 36% of FEA, respectively. Excisional biopsies in 48 of 56 patients demonstrated ductal carcinoma in situ and/or invasive carcinoma in 10 patients (21%), lobular carcinoma in situ or atypical lobular hyperplasia in 5 (11%), residual ADH in 11 (23%), and no atypia in 24 patients (50%). Three (21%) of 14 pure FEA upgraded to ductal carcinoma in situ and/or invasive carcinoma on excisional biopsy. The staining for Ki-67 in FEA/ADH was similar regardless of whether they were upgraded to carcinoma or not. In summary, we found a strong association between FEA and ADH, which may reflect a biologic progression. Most FEAs have a low-power appearance of a well-circumscribed group of ducts. Chronic inflammation and stromal changes are present in a subset of cases. Flat epithelial atypia shows a risk of upgrade to carcinoma similar to that of ADH and, hence, should be recognized and warrants a follow-up excision.     

Breast calcifications with percutaneous vacuum-assisted biopsy diagnosis of malignancy or atypical hyerplasia: correlations with surgical findings

Percutaneous, stereotactic, vacuum-assisted biopsy has become a widely used alternative to open surgical biopsy for the initial diagnosis of breast calcifications. We retrospectively assessed the accuracy of the technique in the diagnoses of malignancy and atypical hyperplasia by correlation with the findings of the subsequent surgical excision. We studied 330 consecutive cases of breast calcifications, 216 (65.5%) of which were determined to be benign and 114 (34.5%) to be malignant or atypical at vacuum-assisted biopsy using an 11 gauge instrument. Of the latter 93 were available for comparison with the subsequent surgery, the specific diagnoses as revealed by percutaneous biopsy were as follows: 11 cases of atypical ductal hyperplasia (ADN), 67 cases of ductal carcinoma in situ (DCIS), 6 infiltrating ductal carcinomas (IFDC), 2 cases of atypical lobular hyperplasia and 7 of lobular carcinoma in situ (LCIS). At histological analysis after surgical excision, 3 (27%) of 11 cases previously diagnosed as ADH and 6 (9%) of 67 cases diagnosed as DCIS were shown to actually be higher grade lesions (DCIS/IFDC and IFDC, respectively). Of the 7 lesions diagnosed at vacuum-assisted biopsy as LCIS, surgery and histological analysis showed one infiltrating globular carcinoma and two DCIS. A total of 21 lesions (4 ADH, 14 DCIS, 1 IFDC, 2 LCIS) were completely removed at percutaneous biopsy; the remaining cases were found totally concordant. These data Indicate a substantial accuracy of the percutaneous biopsy: some lesions (particularly those thought to be ADH and DCIS) can be underestimated for sampling error.     

Nuclear cytometric changes in breast carcinogenesis

Breast cancer is thought to originate through progressively aberrant precursor lesions, paralleled by increasing morphological changes. The aim of this study was to quantify nuclear features by image cytometry in invasive breast cancer and its early (hyperplasia) and late (ductal carcinoma in situ) precursor lesions, in order to objectively describe nuclear changes in the spectrum of proliferative intraductal and invasive breast lesions. Image cytometry was performed on tissue sections of 20 samples of normal breast tissue, 71 of usual ductal hyperplasia (UDH), nine of atypical ductal hyperplasia (ADH), and 11 of well-differentiated and 13 of poorly differentiated ductal carcinoma in situ (DCIS) lesions. The invasive breast carcinomas consisted of 19 well-differentiated and 24 poorly differentiated lesions. Through the spectrum from normal breast tissue to invasive carcinoma, progressive changes in many nuclear features were measured. Significant differences were found between nuclei of florid ductal hyperplasia compared with mild and moderate ductal hyperplastic lesions, suggesting that florid ductal hyperplasia may be a more advanced lesion than assumed and may contain cancer precursor cells. No differences were found between ADH and well-differentiated DCIS, suggesting that these lesions are closely related. Feature values of well-differentiated DCIS were comparable to values found in well-differentiated invasive carcinoma and the same applied to poorly differentiated DCIS and invasive lesions. These results support the hypothesis that breast cancer develops through different routes of progression, one leading to well-differentiated invasive cancer through well-differentiated DCIS, and one leading to poorly differentiated invasive cancer through poorly differentiated DCIS. In conclusion, image cytometry reveals progressive changes in nuclear morphological and subvisual chromatin distribution features in the spectrum from intraductal proliferations to invasive breast cancer. This provides evidence for a progression from usual to atypical ductal hyperplasia and then to invasive cancer, through different routes for well-differentiated and poorly differentiated lesions.     

Surgical excision is warranted following a core biopsy diagnosis of mucocoele-like lesion of the breast

AIMS: Mucocoele-like lesions (MLLs) of the breast are unusual lesions in which mucin-filled ducts or cysts are accompanied by extrusion of mucin into surrounding stroma. A possible diagnosis of MLL may be suggested by the finding of mucin-filled ducts or cysts and/or stromal mucin in a core biopsy sample. Whether such findings should prompt immediate open diagnostic biopsy to exclude malignancy is currently uncertain, although this represents current practice in our institution. In this study we have reviewed 11 cases of possible MLL on core biopsy correlating both pathological and radiological findings in order to determine the risks of associated malignancy and whether excision is the most appropriate management option. METHODS AND RESULTS: Eleven cases of possible MLL presenting via the Breast Screening and Assessment Unit in Leeds since April 1999 were identified by review of pathological records. Histological slides, mammograms and ultrasound images were reviewed. Ten of the 11 had undergone open surgical biopsy for diagnosis. Three of the 10 (30%) proved to derive from malignant lesions. Two were ductal carcinoma in situ (DCIS) and one was an invasive mucinous carcinoma. All three cases had an associated atypical epithelial proliferation which, in a surgical excision, would be classified as atypical ductal hyperplasia (ADH) at least, as well as mucin in the core biopsy sample. The majority of possible MLLs presented radiologically as coarse calcification, but two of four (50%) which had a radiological mass subsequently proved malignant. Seven cases were without atypia on the core and all subsequently proved benign. Three of these, however, were associated with ADH on the excision biopsy. CONCLUSION: Surgical excision is warranted following a core biopsy suggestion of possible MLL when mucin-filled ducts or cysts and stromal mucin have been seen. The risk of malignancy is high when the core biopsy also contains an atypical epithelial proliferation (100% in our series) and also when there is an associated radiological mass lesion. In cases without atypia on the core a significant proportion of cases (43%) are associated with ADH on excision.     

Immunohistochemical staining for cyclin D1 and Ki-67 aids in the stratification of atypical ductal hyperplasia diagnosed on breast core biopsy

A diagnosis of atypical ductal hyperplasia (ADH) after breast core biopsy usually is followed by an excisional biopsy to exclude the presence of a more significant lesion. To determine whether the immunohistochemical expression of cyclin D1 (CyD1) and Ki-67 can aid in case stratification for the likelihood of finding ductal carcinoma in situ (DCIS) on subsequent excision, we immunohistochemically stained 21 consecutive ADH cases diagnosed by core biopsy, and proliferation indices (PIs) were calculated for each case. Fluorescence in situ hybridization to detect CCND1 amplification was performed in 10 cases. In 5 cases, DCIS (with or without invasive carcinoma) was identified in the subsequent excision. The mean PICyD1 and PIKi-67 for these cases were significantly higher than in the remainder (P = .03 and P = .05, respectively). The sensitivities of PICyD1 and PIKi-67 for the presence of DCIS on subsequent excision were 100%, and the specificities were 75% and 69%, respectively. The specificity of the 2 markers combined was 88%. The number of cells with CCND1 amplification was higher in cases with DCIS or ADH on subsequent excision. Immunostaining for CyD1 and Ki-67 might help stratify cases of ADH on core biopsy and identify patients unlikely to have DCIS found on excision.     

CEA and HMFG in hyperplastic and malignant lesions of the breast

In order to evaluate a possible transition from proliferative lesions of the breast to ductal carcinoma in situ (DCIS), an immunohistochemical retrospective analysis was carried out. Twelve patients with hyperplasia without atypia, 11 patients with hyperplastic lesions with atypia, 21 patients with DCIS and 24 patients with invasive carcinoma were studied. The expression of carcino-embryonic antigen (CEA), a dedifferentiation marker, was investigated, applying one monoclonal antibody (Amersham). The expression of human milk fat globulin (HMFG), a differentiation marker, was studied by means of three monoclonal antibodies. The results reveal that no CEA activity can be demonstrated in normal and hyperplastic breast tissue, either with or without atypia. The monoclonal antibody was positive in 48% of DCIS and 50% of the invasive carcinomas. We failed to observe a correlation between the presence of CEA and the differentiation of the tumor. The application of this antiserum adds no substantial information about the phenotypic alterations during the progression from atypical hyperplasia to DCIS. HMFG was present in benign as well as in malignant breast lesions. Therefore, we conclude that HMFG is not useful for the evaluation of the phenotypic change from atypical hyperplasia to malignancy. However, as pointed out by others, it can be used in a diagnostic panel of different antibodies in the distinction between epithelial and non-epithelial lesions.     

Quantitative analysis of allele imbalance supports atypical ductal hyperplasia lesions as direct breast cancer precursors

It remains unclear whether hyperplastic breast lesions, especially with atypia, are cancer precursors or markers of increased cancer risk. Quantified comparisons of genomic alterations in coexisting lesions could address this question. Therefore, we examined allele imbalance (AI), also known as loss of heterozygosity (LOH), at 20 microsatellite markers on nine chromosome arms, in DNA from 106 samples microdissected from 17 randomly selected cancer-containing breast specimens: 13 simple (DH) and 45 atypical ductal hyperplastic (ADH) lesions, 30 in situ (DCIS) and 18 invasive ductal carcinomas (IDC). Data were analysed using regression models and generalized estimating equations. We found that AI increased as histology became more aberrant and varied with histology across the chromosome arms (p<0.0001). ADH had more AIs on 1q (p=0.03) and 16q (p=0.02) and fewer AIs on 17p (p=0.06) and 17q (p<0.0001) than on other arms. In cancers, AIs remained high on 1q and 16q, and became frequent on 17p and 17q. Concordance between AIs in ADHs and cancers exceeded the 50% expected if the lesions were separate clones in 16/20 (80%) ADHs (p=0.05), from 9/11 (82%) cases (p=0.03), and involved 41/51 (80%) evaluable markers (p=0.05). The occurrence of any AI in ADH predicted greater AI (p=0.009) and possibly lower grade (p=0.05) in coexisting cancers. Nevertheless, ADHs were not genetically identical to cancers or to each other. We found AIs discordant between ADHs and cancers (always on 1q and 16q), AIs unique to ADH (usually on 11q) and some genetic heterogeneity among coexisting ADHs. We conclude that ADH lesions are genetically advanced, with frequent alterations on 1q and 16q, and are often direct cancer precursors. Their global genetic characteristics predict features of cancers in the same breast. Nevertheless, the genetic heterogeneity detected suggests that hyperplasias and cancers may arise on a field at generalized increased cancer risk.     

Value of cytokeratin 5/6 immunostaining using D5/16 B4 antibody in the spectrum of proliferative intraepithelial lesions of the breast. A comparative study with 34βE12 antibody

Previous studies have shown that basal-type cytokeratins (CKs) can distinguish usual ductal hyperplasia (UDH) from the spectrum of atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS). Indeed, expression of these CKs is weak or absent in ADH, DCIS and LCIS. However, the diagnostic usefulness of D5/16B4 antibody (anti-CK5/6) has never been compared with that of 34betaE12 antibody (anti-CK1/5/10/14). We performed immunostaining of CK 5/6 and CK1/5/10/14 on 100 breast lesions, including UDH ( n=31), ADH ( n=5), DCIS ( n=54) and LCIS ( n=10). Abundant immunostaining was observed in all UDH using both antibodies. Four of five of the ADH cases showed less than 5% of CK5/6 stained cells, the remaining case showed 30% of labeled cells. With 34betaE12 antibody, three of five of the ADH cases showed less than 5% labeled cells, while two cases showed more than 30% of stained cells. None of the 54 DCIS or the 10 LCIS was labeled by D5/16B4, while a lack of 34betaE12 immunostaining was observed in only 15 of 54 DCIS and 2 of 10 LCIS. We confirmed that D5/16B4 antibody directed against CK5/6 is useful in distinguishing UDH from the spectrum of ADH/DCIS/LCIS. We also demonstrated that D5/16B4 is far a more specific marker than 34betaE12 antibody.     

Analysis of loss of heterozygosity on chromosome 11q13 in atypical ductal hyperplasia and in situ carcinoma of the breast.

Identical allelic loss in invasive and adjacent in situ ductal breast carcinoma (DCIS) on chromosome 11q13 has been previously reported, providing molecular evidence for the progression of DCIS to invasive tumor. In this study we analyzed loss of heterozygosity (LOH) on 11q13 (PYGM, INT-2) in atypical ductal hyperplasia (ADH) and various histological types of in situ carcinomas of the breast in patients without invasive cancer. Twenty-four cases of in situ carcinoma and twelve cases of ADH were studied. Tissue microdissection of normal, hyperplastic, and tumor cells from fixed, paraffin-embedded sections was performed, and DNA was extracted for polymerase chain reaction. In situ tumors included both high- and low-grade DCIS. LOH was identified in six of twenty-two (27.3%) in situ tumors and in one of eleven (9%) ADH cases. Within in situ carcinomas, LOH was identified in six of seventeen (35%) high-grade DCIS but in none of six low-grade DCIS. The present results show that LOH at 11q13 occurs in an appreciable proportion of high-grade DCIS, although the rate is substantially less than in patients with concomitant DCIS and invasive tumor. LOH was identified less frequently in low-grade in situ tumors and ADH, suggesting that a putative tumor suppressor gene(s) located on chromosome 11q13 may be involved in the transition from early preneoplastic lesions to invasive breast cancer.     

The low nuclear grade breast neoplasia family

Breast cancer is a heterogeneous disease with varied morphological and molecular features and clinical behaviour. Recently a group of invasive tumours and precursor lesions was reported to exhibit strikingly similar low-grade nuclear features, immunophenotypic and molecular profiles and coexist at frequencies that could not be justified by chance alone. These lesions are grouped together into a single class termed low-grade breast neoplasia family (LGBNF) to differentiate them from high-grade neoplasms, which are thought to develop through different evolutionary pathways. Precursor lesions in this family include columnar cell lesions (CCLs), flat epithelial atypia (FEA), atypical ductal hyperplasia (ADH), atypical lobular hyperplasia (ALH), lobular carcinoma in-situ (LCIS) and low-grade DCIS. Invasive LGBNF tumours include invasive tubular and cribriform carcinomas, invasive lobular carcinoma, low-grade invasive mucinous and low-grade ductal no special type (NST) carcinomas. These lesions are characterized by strong uniform expression of hormone receptors, lack of HER2 expression and HER2 gene amplification, and exhibit a unique pattern of genetic aberrations mainly deletions of 16q and gains of 1q. In this review, we present the concept of LGBNF with emphasis on their characteristic phenotypic, genotypic and molecular profiles and their impact on BC management strategies and discuss a hypothetical model of breast cancer evolution and progression.     

Discrepancies in the diagnosis of intraductal proliferative lesions of the breast and its management implications: results of a multinational survey

To measure discrepancies in diagnoses and recommendations impacting management of proliferative lesions of the breast, a questionnaire of five problem scenarios was distributed among over 300 practicing pathologists. Of the 230 respondents, 56.5% considered a partial cribriform proliferation within a duct adjacent to unequivocal ductal carcinoma in situ (DCIS) as atypical ductal hyperplasia (ADH), 37.7% of whom recommended reexcision if it were at a resection margin. Of the 43.5% who diagnosed the partially involved duct as DCIS, 28.0% would not recommend reexcision if the lesion were at a margin. When only five ducts had a partial cribriform proliferation, 35.7% considered it as DCIS, while if ≥20 ducts were so involved, this figure rose to 60.4%. When one duct with a complete cribriform pattern measured 0.5, 1.5, or 4 mm, a diagnosis of DCIS was made by 22.6, 31.3, and 94.8%, respectively. When multiple ducts with flat epithelial atypia were at a margin, 20.9% recommended reexcision. Much of these discrepancies arise from the artificial separation of ADH and low-grade DCIS and emphasize the need for combining these two under the umbrella designation of ductal intraepithelial neoplasia grade 1 (DIN 1) to diminish the impact of different terminologies applied to biologically similar lesions.     

Amplification of Her-2/neu gene in Her-2/neu-overexpressing and -nonexpressing breast carcinomas and their synchronous benign, premalignant, and metastatic lesions detected by FISH in archival material.

Amplification of Her-2/neu in breast carcinoma is associated with poor prognosis, short disease-free interval, and short survival time in both node-negative and -positive patients. Little is known about the starting point of amplification of Her-2/neu and how it progresses from benign to malignant breast lesions. We attempted to address these questions by evaluating amplification of Her-2/neu in benign, premalignant, and malignant lesions using fluorescence in situ hybridization (FISH). Twenty-six patients with Her-2/neu-overexpressing invasive ductal carcinomas (as judged by strong immunoreactivity with Her-2/neu antibody) and coexisting lesions of ductal hyperplasia (DH), atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS) in the vicinity of the invasive tumor (as judged by review of the hematoxylin and eosin-stained sections), as well as metastatic carcinoma in axillary lymph nodes (mets) were selected for this study. In the primary carcinomas, a close relationship was present between overexpression as detected by immunohistochemistry (IHC) and amplification as demonstrated by FISH (85% concordance). Among these patients, amplification of Her-2/neu in ADH was demonstrated in 7 of 13 cases with ADH, and in DCIS, in 21 of 22 cases with DCIS. There was no amplification in DH or normal ductal epithelium. Significantly, in all 12 patients with synchronous positive axillary lymph nodes, there was concordant amplification of Her-2/neu in the primary and metastatic carcinoma. Amplification was consistent in multifocal metastases, despite morphological heterogeneity in some patients. Amplification ratios increased from ADH to DCIS to invasive carcinoma (P <.01, ADH versus DCIS; P <.05, DCIS versus invasive cancer), but there was no difference in amplification ratios between primary cancers and synchronous axillary metastases (P >.05). We also evaluated Her-2/neu amplification in 21 patients without Her-2/neu overexpression in their primary carcinomas (as judged by absent immunoreactivity with Her-2/neu antibody). Three showed amplification in both primary and metastatic lesions, with a low amplification ratio (approximately 2). One patient had amplification in the primary tumor but not in an axillary metastasis. Two patients exhibited slight amplification in the metastatic carcinoma (ratios 1.6 and 2), but not in their primary cancers. This FISH study indicates that amplification of Her-2/neu can emerge de novo in any stage of the disease process, from ADH to metastatic lesions, but most often appears first in ADH or DCIS. The degree of Her-2/neu amplification increases with progression to invasive carcinoma, there being no further increase in synchronous metastasis. Our data suggest that amplification of Her-2/neu appears to be mainly involved in initiation of breast oncogenesis and that its role in progression of breast cancers is uncertain.