A clinicopathologic study of atypical lesions of the breast further follow up

Why the term 'low-grade ductal carcinoma in situ' should be changed to 'borderline breast disease': diagnostic and clinical implications

During the last several years, increased public awareness, advances in breast imaging and enhanced screening programs have led to early breast cancer detection and attention to cancer prevention. The number of image-detected biopsies has increased, and pathologists are expected to provide more information with smaller tissue samples. These biopsies have resulted in detection of increasing numbers of high-risk proliferative breast disease and in situ cancers. The general hypothesis is that some forms of breast cancers may arise from established forms of ductal carcinoma in situ and atypical ductal hyperplasia, and possibly from more common forms of ductal hyperplasia. However, this is an oversimplification of a very complex process given the fact that the majority of breast cancers appear to arise de novo or from a yet unknown precursor lesion. Currently, atypical ductal hyperplasia and ductal carcinoma in situ are considered as morphologic risk factors and precursor lesions for breast cancer. However, morphologic distinction between these two entities has remained a real issue that continues to lead to overdiagnosis and overtreatment. Aside from morphologic similarities between atypical ductal hyperplasia and low-grade ductal carcinoma in situ, biomarker studies and molecular genetic testing have shown that morphologic overlaps are reflected at the molecular level and raise questions about the validity of separating these two entities. It is hoped that as we better understand the genetic basis of these entities in relation to ultimate patient outcome, the suggested use of the term 'borderline breast disease' can minimize the number of patients who are subject to overtreatment.

Atypical ductal hyperplasia: interobserver and intraobserver variability

Interobserver reproducibility in the diagnosis of benign intraductal proliferative lesions has been poor. The aims of the study were to investigate the inter- and intraobserver variability and the impact of the addition of an immunostain for high- and low-molecular weight keratins on the variability. Nine pathologists reviewed 81 cases of breast proliferative lesions in three stages and assigned each of the lesions to one of the following three diagnoses: usual ductal hyperplasia, atypical ductal hyperplasia and ductal carcinoma in situ. Hematoxylin and eosin slides and corresponding slides stained with ADH-5 cocktail (cytokeratins (CK) 5, 14. 7, 18 and p63) by immunohistochemistry were evaluated. Concordance was evaluated at each stage of the study. The interobserver agreement among the nine pathologists for diagnosing the 81 proliferative breast lesions was fair (κ-value=0.34). The intraobserver κ-value ranged from 0.56 to 0.88 (moderate to strong). Complete agreement among nine pathologists was achieved in only nine (11%) cases, at least eight agreed in 20 (25%) cases and seven or more agreed in 38 (47%) cases. Following immunohistochemical stain, a significant improvement in the interobserver concordance (overall κ-value=0.50) was observed (P=0.015). There was a significant reduction in the total number of atypical ductal hyperplasia diagnosis made by nine pathologists after the use of ADH-5 immunostain. Atypical ductal hyperplasia still remains a diagnostic dilemma with wide variation in both inter- and intraobserver reproducibility among pathologists. The addition of an immunohistochemical stain led to a significant improvement in the concordance rate. More importantly, there was an 8% decrease in the number of lesions classified as atypical ductal hyperplasia in favor of usual hyperplasia; in clinical practice, this could lead to a decrease in the number of surgeries carried out for intraductal proliferative lesions.

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 >or=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.

The prevalence of carcinoma in situ in normal and cancer-associated breasts

Two hundred ninety-two human breasts were examined in toto by a subgross sampling technique with histologic confirmation. The samples consisted of 185 breasts from random autopsies, 63 cancer-containing breasts, and 44 breasts contralateral to cancer-containing breasts. The method permits the identification and enumeration of essentially all of the dysplastic, hyperplastic, and neoplastic lesions present in each breast. Emphasis was on the prevalence within each sample category of ductal carcinoma in situ (DCIS), lobular carcinoma in situ (LCIS), and epithelial proliferative lesions with severe atypia, previously termed ALA 4 and ALB 4, which correspond to the clinicopathologic entities atypical ductal hyperplasia and atypical lobular hyperplasia, respectively. Additional primary foci of DCIS (unrelated to invasive breast carcinoma, if present) were found in 52.5 per cent of cancer-containing breasts, and were seen in 47.7 per cent of contralateral and 5.9 per cent of the breasts from random autopsies. Lobular carcinoma in situ was generally seen only in association with infiltrating carcinoma, usually of the ductal type. No LCIS was seen in the breasts from random autopsies. These trends are the same if the proliferative lesions with severe atypia are included with carcinoma in situ. The numbers of lesions were also markedly greater in affected cancer-associated breasts than in affected breasts obtained from autopsies. These findings suggest that LCIS, although a rare lesion in the general population, may be a significant marker for clinical carcinoma. They support previous studies showing a small percentage of women with undetected DCIS of uncertain clinical and biological potential. The multicentric nature of preinvasive breast carcinoma is further substantiated. Finally, when the prevalence and number of lesions are considered in association with the ages of the patients, the lower prevalence of such lesions in the older patients in each sample suggests that at least some DCIS and LCIS may be dependent on a premenopausal hormonal milieu for their continuing existence.