Central atypical papillomas of the breast: a clinicopathological study of 119 cases

The clinicopathological features of central intraductal papillomas of the breast presenting with florid usual ductal hyperplasia or atypical ductal hyperplasia (ADH) were analyzed in a retrospective series of 119 patients, whose lesions were sent to the Armed Forces Institute of Pathology from 1976 to 1990. After histological review considering predefined morphological and quantitative criteria, the 119 central papillomas were classified into 22 papillomas with florid usual ductal hyperplasia (18%), 40 papillomas with focal atypia (34%), 24 atypical papillomas (20%) and 33 carcinomas arising in a papilloma (28%). After a median period of follow-up of 110 months, 16 recurrences (5 papillomas, 2 carcinomas arising in a papilloma, 4 ductal carcinomas in situ, 5 invasive carcinomas) occurred. No statistically significant difference was observed in relation to recurrence for the various categories of papillomas. The presence of epithelial hyperplasia, ADH or lobular neoplasia in the surrounding breast as well as infarction of the papilloma were significant predictive factors of recurrence (P=0.02 and P=0.005, respectively, log-rank test). The main reason for the observed low rate of significant recurrences in this series was that epithelial atypia (whether comprising 20% or 60% of the papillary lesion) was, in most of the cases, localized in a confined lesion that was completely excised.     

Molecular cytogenetic comparison of apocrine hyperplasia and apocrine carcinoma of the breast

The relationship of apocrine metaplasia to invasive breast cancer is controversial. Different authors have reported that apocrine differentiation in proliferative lesions may be a risk factor, a precursor lesion, or have no association with malignancy. The aim of this study was to compare the genetic alterations in benign apocrine hyperplasia with apocrine ductal carcinoma in situ (DCIS) and invasive apocrine carcinomas of the breast using comparative genomic hybridization. The mean number of alterations in apocrine hyperplasia was 4.1 (n = 10) compared to 10.2 in apocrine DCIS (n = 10) and 14.8 (n = 4) in invasive carcinoma. The most common alterations in apocrine hyperplasia were gains of 2q, 13q, and 1p and losses of 1p, 17q, 22q, 2p, 10q, and 16q. Apocrine DCIS and invasive carcinomas showed gains of 1q, 2q, 1p, and losses of 1p, 22q, 17q, 12q, and 16q as their most common DNA copy number changes. Apocrine hyperplasia is considered to be a benign lesion and its relationship to invasive carcinoma remains unclear. Our data suggest that some apocrine hyperplasias may be clonal proliferations. The mean number of alterations are lower in apocrine hyperplasia, however the changes show considerable overlap with those identified in in situ and invasive apocrine carcinoma. These alterations are also commonly seen in nonapocrine breast cancer. The data are consistent with apocrine hyperplasia as a putative nonobligate precursor of apocrine carcinoma.     

Atypical ductal hyperplasia of the breast: clonal proliferation with loss of heterozygosity on chromosomes 16q and 17p.

AIMS--To determine if allelic loss on chromosomes 16q and 17p, commonly encountered in in situ and invasive ductal carcinomas, is present in atypical ductal hyperplasia (ADH); to determine whether ADH is a neoplastic (clonal) or hyperplastic (polyclonal) proliferation. METHODS--Fourteen cases of ADH were examined for allele loss at loci on chromosome 16q and 17p using a microdissection technique, polymorphic DNA markers and the polymerase chain reaction (PCR). RESULTS--Loss of heterozygosity (LOH) was detected in five of nine informative cases on chromosome 16q at the microsatellite D16S413 and two of eight informative cases on chromosome 17p at D17S796. CONCLUSIONS--The incidence of LOH at these loci is similar to that previously observed in ductal carcinoma in situ and in invasive ductal carcinoma. Because of the nature of the technique used, our findings also demonstrate that ADH is a monoclonal, and hence, neoplastic proliferation rather than a hyperplastic (polyclonal) condition as its name suggests. There is thus a case for including ADH, as presently defined, within the spectrum of ductal carcinoma in situ.     

Monoclonality in normal epithelium and in hyperplastic and neoplastic lesions of the breast

The clonal nature of neoplastic lesions such as invasive breast cancer and ductal carcinoma in situ (DCIS) has been widely proven by several proliferative, genetic or other malignancy-associated markers. The aim of this study is to clarify whether benign hyperplastic lesions such as ductal hyperplasia of usual type (DH) and papilloma can be distinguished from neoplastic lesions such as DCIS by X-chromosome inactivation analysis. Clonal analysis was performed using a polymerase chain reaction-based assay for non-random X-chromosome inactivation of the human androgen receptor gene (HUMARA). Formalin-fixed and paraffin-embedded archival tissue of ten DCIS, sixteen DH, nine papillomas, and seven normal terminal ductal lobular units (TDLUs) was laser-microdissected to avoid contamination with surrounding tissue. All of the cases analysed revealed a monoclonal origin. Furthermore, in one of these cases, opposite X chromosomes were inactivated within the same breast. X-linked inactivation analysis clearly demonstrates that, at least in the breast, monoclonality is not restricted to neoplastic processes. The data support the hypothesis that the mammary gland is organized into distinct stem cell-derived monoclonal patches and that TDLUs are monoclonal in origin. Any proliferative lesion arising within such a pre-existing clonal patch should therefore be clonal, irrespective of whether it originates from one or more patch cells. Thus, X-chromosome inactivation analysis cannot be considered a valid method for distinguishing between neoplastic and hyperplastic breast lesions.     

Cytokeratin 5/6 immunohistochemistry assists the differential diagnosis of atypical proliferations of the breast

AIMS: This study was performed to determine the diagnostic value of keratin 5/6 (CK 5/6) immunophenotyping on routinely processed breast tissues. METHODS AND RESULTS: Six hundred and ninety-nine breast lesions, including normal tissues as well as benign and malignant lesions in 321 formalin-fixed, paraffin-embedded samples from 158 different patients were investigated immunohistochemically, following wet autoclave pre-treatment for antigen retrieval. In normal breast tissues, both myoepithelial and luminal epithelial cells expressed CK 5/6 in varying amounts. While myoepithelial immunoreactivity was most pronounced in the duct system, luminal epithelial immunoreactivity was strongest in the terminal duct lobular units. In ductal hyperplasias (DH), luminal epithelial cells predominantly revealed CK 5/6 immunoreaction. In contrast, neoplastic epithelial cells in atypical ductal and lobular hyperplasias (ADH and ALH) lacked such an expression, whereas in ductal in-situ carcinomas (DCIS) and in infiltrating ductal carcinomas 3.7% and 7.7%, of the cases respectively, showed positive immunostaining for CK 5/6. CONCLUSIONS: Immunophenotyping of keratin 5/6 expression can be helpful in the diagnosis of atypical hyperplasias and in-situ carcinomas of the breast. It is particularly valuable in the differential diagnosis between benign and atypical proliferative lesions.     

A case of double primary adenocarcinoma of the lung with multiple atypical adenomatous hyperplasia

A case of double primary adenocarclnoma of the lung with multiple atypical adenomatous hyperplasla (AAH) In a 77-year-old woman Is reported. Hlstopathologlcally, in the resected left upper lobe of the lung, both cancers were diagnosed as well-differentlated papillary adenocarcinoma, and 161 lesions of AAH were also found. Both the cancer lesions and six AAH (greater than 3 mm In diameter) were examined wlth regard to immunoreactivity of carcinoem-bryonlc antigen (CEA) and p53 gene product, microsatellite lnstabllity (MI) and loss of heterozygosity (LOH) on chromosome 9q and 17q by polymerase chain reaction (PCR). Although both cancers expressed CEA, they did not show clonal lmmunoreactivity for the p53 gene product. Atypical adenomatous hyperplasia expressed CEA weakly and showed no immunoreactlvity for p53 gene protein. Both carcinomas showed LOH on chromosome 17q, and one of them showed LOH on chromosome 9q. In six AAH, LOH on chromosome 17q was detected In two tumors, and one of them also showed LOH on chromosome 9q. One AAH, which was negative for LOH on chromosome 17q and 9q, showed Mi at D17S791. These results indicated that AAH is a clonal neoplastic lesion with genetic abnormalities and should be called intraepithelial pneumocyte neoplasia, and that each of the numerous papillary lesions in this case was considered to be an Independent lesion.     

Loss of heterozygosity is detected at chromosomes 1p35-36 (NB), 3p25 (VHL), 16p13 (TSC2/PKD1), and 17p13 (TP53) in microdissected apocrine carcinomas of the breast.

INTRODUCTION: Apocrine carcinomas of the breast are an unusual special category of predominantly AR+, ER-, and PR- breast cancer, characterized by cells with abundant, eosinophilic cytoplasm and nuclei with often prominent nucleoli. To further investigate these lesions, loss of heterozygosity (LOH) was evaluated at multiple chromosomal loci, including loci frequently mutated in breast cancer. MATERIALS AND METHODS: Twenty-five intraductal apocrine carcinomas, 11 invasive apocrine carcinomas, and six apocrine hyperplasias were retrieved from the files of the Armed Forces Institute of Pathology (Washington, DC) and Fairfax Hospital (Fairfax, VA). Cells from lesional as well as normal tissues were microdissected. LOH was performed at a number of chromosomal loci, including loci commonly altered in breast cancer: 1p35-36 (NB), 3p25.5 (VHL), 8p12 (D8S136), 9p21 (p16), 11p13 (D11S904), 11q13 (INT-2 and PYGM), 16p13.3 (TSC2/PKD1 gene region), 17p13 (TP53), 17q13 (NM23), and 22q12 (D22S683). RESULTS: Among informative in situ and invasive apocrine carcinomas, LOH was present in 33% of 15 cases for 17p13 (TP53), as well as 36% of 14 cases for 3p25 (VHL), 30% of 10 cases for 1p35-36 (NB), and 27% of 11 cases for 16p13.3 (TSC2/PKD1). A higher frequency of LOH was noted among invasive apocrine carcinomas (30 to 50%) compared with in situ apocrine carcinomas (23 to 33%) at these loci. LOH was present simultaneously for TP53 and either VHL or NB in five cases. Infrequent (< or =12%) or absent LOH was detected at the remaining loci, including several loci commonly mutated in breast cancer (i.e., INT2, PYGM, and NM23). LOH was not detected in any of the six apocrine hyperplasias. CONCLUSION: An intermediate frequency of allelic loss was detected at multiple tumor suppressor gene loci, including 17p13 (TP53), as well as 1p35-336 (NB), 3p25 (VHL), and 16p13 (PKD1/ TSC2), in apocrine carcinomas of the breast, with a higher overall frequency of LOH noted among invasive tumors compared with in situ tumors. Aside from LOH at p53, LOH was infrequent or absent at several other loci commonly mutated in breast cancer. This preliminary molecular evidence supports immunohistochemical data that apocrine carcinomas of the breast may possess unique mechanisms of carcinogenesis, compared with ordinary ductal carcinomas. However, further study is needed to support this assertion and to determine if the LOH detected is truly etiologic or if it is the result of genetic progression.     

Frequent genetic alterations in flat urothelial hyperplasias and concomitant papillary bladder cancer as detected by CGH,LOH, and FISH analyses

Flat urothelial hyperplasia, defined as markedly thickened urothelium without cytological atypia, is regarded in the new WHO classification as a urothelial lesion without malignant potential. Frequent deletions of chromosome 9 detected by fluorescence in situ hybridization (FISH) have been previously reported in flat urothelial hyperplasias found in patients with papillary bladder cancer. Using comparative genomic hybridization (CGH) and microsatellite analysis, these hyperplasias and concomitant papillary tumours of the same patients were screened for other genetic alterations to validate and extend the previous findings. Eleven flat hyperplasias detected by 5-ALA-induced fluorescence endoscopy and ten papillary urothelial carcinomas (pTaG1-G2) from ten patients were investigated. After microdissection, the DNA of the lesions was pre-amplified using whole genome amplification (I-PEP-PCR). Loss of heterozygosity (LOH) analyses were performed with five microsatellite markers at chromosomes 9p, 9q, and 17p. CGH was performed using standard protocols. In 6 of 11 hyperplasias and 7 of 10 papillary tumours, deletions at chromosome 9 were simultaneously shown by FISH, LOH, and CGH analyses. There was a good correlation between FISH, LOH, and CGH analyses, with identical results in 6 of 10 patients. In addition to deletions at chromosome 9, further genetic alterations were detected by CGH in 9 of 10 investigated hyperplasias, including changes frequently found in invasive papillary bladder cancer (loss of chromosomes 2q, 4, 8p, and 11p; gain of chromosome 17; and amplification at 11q12q13). There was considerable genetic heterogeneity between hyperplasias and papillary tumours, but a clonal relationship was suggested by LOH and/or CGH analyses in 5 of 10 cases. These data support the hypothesis that flat urothelial hyperplasias can display many genetic alterations commonly found in bladder cancer and could therefore be an early neoplastic lesion in the multistep development of invasive urothelial carcinoma.     

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.     

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.     

Papillomas and atypical papillomas in breast core needle biopsy specimens: risk of carcinoma in subsequent excision

We sought to define the risk associated with papillomas and atypical papillomas in breast core needle biopsy specimens from a series of approximately 8,500 biopsies performed during 8 years. From a total of 62 papillary lesions (including papillomas and atypical papillomas), 40 (65%) had histologic follow-up. Overall, 15 (38%) of 40 patients had ductal carcinoma in situ (12 cases) or invasive carcinoma at excision (3 cases). Eight cases diagnosed as papilloma had benign follow-up. Slides were available for review in 38 cases and reclassified into benign papilloma with florid hyperplasia and no or minimal atypia (18 cases), papilloma with separate foci of atypical ductal hyperplasia (7 cases), and severely atypical papillomas "suspicious" for papillary carcinoma (13 cases). Carcinoma was identified in 0 (0%), 2 (29%), and 12 (92%) cases, respectively. We conclude that while atypical papillary lesions and papillomas with associated atypical ductal hyperplasia in breast core needle biopsy specimens are associated with a risk of carcinoma, lesions diagnosed as papilloma or papilloma with no or minimal atypia are benign and do not need to be excised.     

Breast pathology practice: most common problems in a consultation service

Considerable progress has been made in understanding breast lesions utilizing molecular methods, but conventional morphology, simple immunohistochemical stains and common sense still prevail in diagnosing the vast majority of breast disease. The focus of this review is to identify the most common breast lesions sent to our consultation practice, and to reiterate salient diagnostic features, differential diagnoses and common pitfalls in identifying these lesions. Separation of epithelial proliferative lesions and differentiation between usual epithelial hyperplasia (UEH) and atypical ductal hyperplasia (ADH) are the most common problems encountered in our Consultation practice. Differentiation between UEH and ADH is based on the assumption that ADH is a clonal process, recognized by a uniform phenotype and more recently described immunohistochemical markers such as differential cytokeratin and also hormone receptor expression. Difficulty in subtyping invasive carcinomas and exclusion of in situ and/or invasive carcinoma in a sclerosing lesion is also commonly noted. Finally, problems in distinguishing various papillary and fibroepithelial lesions are also encountered. The use of common immunohistochemical stains such as various cytokeratin and myoepithelial markers, E-cadherin and hormone receptors is helpful in solving most of these diagnostic dilemmas.     

Different proliferative patterns characterize different preinvasive breast lesions

The study of cell-cycle associated proteins Ki-67/MIB-1, bcl-2 and p53 could clarify some features regarding the early phases of neoplastic progression in the breast. An extensive immunohistochemical study was carried out of the expression of these markers in all kinds of preinvasive breast lesions and their collateral normal parenchyma, a type of analysis not previously reported. The specimens were 35 florid ductal hyperplasias (FDHs), 8 atypical ductal hyperplasias (ADHs), 12 well-differentiated intraductal carcinomas (WDICs), 20 intermediately differentiated intraductal carcinomas (IDICs), 14 poorly differentiated intraductal carcinomas (PDICs), 12 atypical lobular hyperplasias (ALHs), 12 type-A lobular carcinomas in situ (LCIS), 150 normal small-size ducts and 365 lobules. All FDHs, ADHs, WDICs, and lobular lesions showed low proliferation (Ki-67/MIB-1), bcl-2 positivity, and p53 negativity; all PDICs expressed high proliferation, while 85 per cent and 7 per cent were p53 and bcl-2 positive respectively; IDICs showed high proliferation (50 per cent), bcl-2 expression (70 per cent), and p53 positivity (30 per cent), but no correlation between the expression of these markers was observed. Independent of the type of collateral lesion and age of the patient, 90 per cent and 10 per cent of small ducts/lobules showed low and high proliferation and diffuse and low bcl-2 expression respectively; no p53 positivity was observed. The modulation of cell proliferation and apoptosis control in ductal lesions could be the expression of a progression from hyperplasia/WDIC to PDIC, in which IDICs represent the link, owing to their immunoprofile. An alternative purely speculative hypothesis is that the different immunoprofile of the preinvasive lesions reflects their different origin in normal breast parenchyma. Low proliferative or bcl-2 positive lobules could be the site of origin of the lesions maintaining this phenotype, namely FDHs, ADHs, WDICs and lobular lesions, while highly proliferative or bcl-2 negative lobules could be the site in which PDICs develop. Consequently, preinvasive breast lesions could express a different regulation of apoptosis control and proliferative activity from the very beginning, rather than a modulation during neoplastic progression. Copyright © 1999 John Wiley & Sons, Ltd.     

Proliferative lesions of the breast: carcinoma in situ

Many breast carcinomas probably arise in a multi-step fashion through a series of intermediate lesions viz. ductal hyperplasia to atypical ductal hyperplasias to ductal carcinoma in situ (DCIS), and thence to invasive ductal cancer, each of which has a greater probability of becoming malignant than the one that preceded it. These precursor lesions have differing risk implications, hence treatment decisions vary with the risk. The heterogeneous lesions that come under the heading of hyperplasias and DCIS can cause problems for the histopathologists unless there is a conceptual understanding of the disease process. Since the surgical pathology report is the final word in cases of DCIS/LCIS, the pathologist becomes a vital partner in the decision making team.     

Accumulation of chromosomal imbalances from intraductal proliferative lesions to adjacent in situ and invasive ductal breast cancer.

Carcinoma of the breast is thought to evolve through a sequential progression from normal to proliferative epithelium and eventually into carcinoma. Here lumpectomy specimens from five patients were studied, selected for the presence of ductal hyperplasia without atypia, atypical ductal hyperplasia, ductal carcinoma in situ, and invasive ductal carcinoma. Laser microdissection of tissue allowed precise sampling and direct correlation of phenotypic and genotypic changes. Analyses of the samples revealed an increasing mean number of chromosomal changes occurring with increasing histologic severity, and for the first time chromosomal abnormalities were demonstrated in ductal hyperplasia without atypia. Chromosomal changes found in each of the four histologic entities included gains on 10q, 12q, 16p, and 20q and loss on 13q. In ductal hyperplasia without atypia, gain on 20q as well as loss on 13q was detected with high frequency (four of five samples). Alterations identified in more than 50% of atypical ductal hyperplasia samples included gains on 3p, 8q, 15q, and 22q and loss on 16q. In ductal carcinoma in situ, gain of DNA on 1q and 17q and loss on 4q were additionally found, and in invasive ductal carcinoma, further gains on 6p, 10q, 11q13, and 17p were identified. The chromosomal alterations occurring in the different histopathologic lesions strongly suggest that these regions harbor tumor suppressor genes or oncogenes significant for the development of ductal carcinoma of the breast.     

E-cadherin alterations in atypical lobular hyperplasia and lobular carcinoma in situ of the breast.

Tumor development from an early lesion through to invasive disease is not a clearly defined progression in the breast. Studies of invasive lobular carcinoma have reported mutations, loss of heterozygosity (LOH) and loss of protein expression in epithelial (E)-cadherin, a protein involved in cell adhesion. Our study examines in situ lobular neoplastic lesions without concurrent invasive carcinoma for E-cadherin gene alterations and protein expression, beta-catenin, alpha-catenin and p120-catenin protein expression, and LOH at the chromosome 16q locus, with the goal of determining the events occurring at the stage of lobular neoplasia. In all, 13 atypical lobular hyperplasia lesions and 13 lobular carcinoma in situ lesions from archived cases were examined. E-cadherin sequence alterations were evaluated using single strand conformation polymorphism and DNA sequencing, and PCR-based LOH analysis was carried out for the 16q locus. Using immunohistochemistry, we assessed protein expression. A total of 23 of 24 lesions evaluated by immunohistochemistry were negative for both E-cadherin and beta-catenin protein expression, and 21 of 23 lesions were negative for alpha-catenin. Cytoplasmic (rather than membrane) localization of p120-catenin was observed in 20 of 21 cases. Lobular carcinoma in situ cases were characterized by mutations; however, atypical lobular hyperplasia cases were not. LOH at 16q was an infrequent event. From our study, we conclude that an altered E-cadherin adhesion complex is an early event affecting atypical lobular hyperplasia as well as lobular carcinoma in situ and occurs prior to progression to invasive disease. However, the loss of protein expression is accompanied by E-cadherin DNA alterations in lobular carcinoma in situ but not in atypical lobular hyperplasia. These cases lacking both protein expression and gene alterations suggest that another mechanism is involved, possibly as early as at the hyperplastic stage, causing silencing of the E-cadherin complex.     

Methylation of CpG islands of p16(INK4a) and cyclinD1 overexpression associated with progression of intraductal proliferative lesions of the breast

P16(INK4a) is a tumor suppressor gene frequently inactivated by aberrant promoter hypermethylation. In this study, p16(INK4a) methylation was evaluated in intraductal proliferative lesions of the breast, using real-time quantitative polymerase chain reaction (MethyLight) and methylation-sensitive restriction endonuclease polymerase chain reaction. Immunohistochemistry was performed to compare and validate the methylation analysis. P16(INK4a) methylation associated with oncogene cyclinD1 expression, detected through the use of in situ hybridization and immunohistochemistry, was likewise characterized. P16(INK4a) methylation displayed varying significance among different types of intraductal proliferative lesions. Both the positive rate and the median quantitative methylation value increased with the evolution of intraductal proliferative lesions through the use of quantitative and qualitative assays. P16(INK4a) methylation was positively correlated to cyclinD1 overexpression. This study demonstrated that p16(INK4a) methylation served as the silencing mechanism of p16(INK4a) protein expression and played a crucial role in the intraductal proliferative lesions' progression. In the differential diagnosis of intraductal proliferative lesions, quantitative DNA methylation analysis of p16(INK4a) by MethyLight may be used as a surrogate, especially to distinguish atypical ductal hyperplasia from usual ductal hyperplasia and low-grade ductal carcinoma in situ. Furthermore, this study discovered that flat epithelial atypia do not share similar molecular profiles of p16(INK4a) epigenetic modification with atypical ductal hyperplasia and low-grade ductal carcinoma in situ.     

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.     

Genetic progression and divergence in pancreatic carcinoma

Genetic alterations of pancreatic intraductal lesions adjacent to invasive ductal carcinoma were investigated. We submitted nine foci of ordinary epithelium, 12 foci of nonpapillary hyperplasia, 12 foci of papillary hyperplasia (pap HP), 66 foci of severe ductal dysplasia, and 27 invasive foci from a total of 10 pancreatic carcinomas for genetic analysis. All foci were individually microdissected and allelic losses of 3p, 4q, 5q, 6q, 8p, 9p, 10q, 11q, 13q, 16q, 17p, and 18q were studied. All invasive and severely dysplastic intraductal foci exhibited loss of heterozygosity (LOH) at more than one chromosomal locus. For each case, allelic loss was frequently observed on 9p (severe ductal dysplasia 90%, invasion 100%), 17p (severe ductal dysplasia 80%, invasion 80%), and 18q (severe ductal dysplasia 88%, invasion 88%). Ninety-four percent of severe ductal dysplasia and 96% of invasive foci had multiple LOH. Seventeen percent of nonpapillary hyperplasia and 33% of pap HP showed LOH. Only one focus of pap HP showed multiple LOH. The patterns of allelic loss identified in severe ductal dysplasia were generally conserved in synchronous infiltrating tumors, supporting the paradigm that infiltrating tumors are clonally derived from severe ductal dysplasia. In eight of 10 cases, however, we found frequent genetic heterogeneity in the intraductal lesion, suggestive of genetic progression or diversion. These findings indicate that invasive pancreatic carcinoma evolves through successive and divergent genetic changes with selection of aggressive subclones in the intraductal component.     

Oestrogen receptors in benign epithelial lesions and intraduct carcinomas of the breast: an immunohistological study

We examined 198 breast lesions, representing commonly encountered benign epithelial proliferative disorders, lobular carcinoma in situ and intraduct carcinoma, immunohistologically for oestrogen receptors (ER). A mixture of three ER monoclonal antibodies--H222, D75 and D547--was used on sections of routinely processed and paraffin-embedded tissue blocks. Over 65% of the benign and malignant lesions showed some evidence of ER expression and significant staining was recorded by two observers in 28-31% of fibroadenomas, 18-28% of ductal epithelial hyperplasias, 30-40% of sclerosing adenosis cases, 38-45% of papillomas, 60% of in situ lobular carcinomas and 42-45% of intraduct carcinomas. Apocrine metaplastic cells and myoepithelial cells showed absent or only weak staining. Amongst intraduct carcinomas, less than 20% of comedo carcinomas and over 50% of cribriform, papillary and solid variants showed significant ER staining.