Clinicopathological characteristics of atypical cystic duct (ACD) of the breast: assessment of ACD as a precancerous lesion

Are Columnar Cell Lesions the Earliest Non-Obligate Precursor in the Low-Grade Breast Neoplasia Pathway?

Columnar cell lesions (CCLs) of the breast comprise a spectrum of morphologic alterations of the terminal duct lobular unit involving variably dilated and enlarged acini lined by columnar epithelial cells. The World Health Organization currently classifies CCLs without atypia as columnar cell change (CCC) and columnar cell hyperplasia (CCH), whereas flat epithelial atypia (FEA) is a unifying term encompassing both CCC and CCH with cytologic atypia. CCLs have been increasingly recognized in stereotactic core needle biopsies (CNBs) performed for the assessment of calcifications. CCLs are believed to represent the earliest non-obligate precursor of low-grade invasive breast carcinomas as they share molecular alterations and often coexist with entities in the low-grade breast neoplasia pathway. Despite this association, however, the risk of progression of CCLs to invasive breast carcinoma appears low and may not exceed that of concurrent proliferative lesions. As the reported upgrade rates of pure CCL/FEA when identified as the most advanced high-risk lesion on CNB vary widely, the management of FEA diagnosed on CNB remains controversial. This review will include a historical overview of CCLs and will examine histologic diagnostic criteria, molecular alterations, prognosis and issues related to upgrade rates and clinical management.

Flat epithelial atypia and risk of breast cancer: A Mayo cohort study

BACKGROUND

Based on its cytologic features, and its co-occurrence with atypical hyperplasia and breast cancer, flat epithelial atypia (FEA) has been proposed as a precursor lesion on the pathway to the development of breast cancer. It is often referred to as an "atypical" or high-risk lesion. However, to the authors' knowledge, the long-term risk of breast cancer in women with FEA is undefined.

METHODS

Specimens with FEA were identified among excisional breast biopsies in the Mayo Clinic Benign Breast Disease Cohort, which includes 11,591 women who had benign biopsy findings at the Mayo Clinic in Rochester, Minnesota between 1967 and 2001. Breast cancer risk among subsets of patients with FEA and nonproliferative, proliferative, and atypical hyperplasia (AH) was assessed using standardized incidence ratios (SIRs) compared with the Iowa Surveillance, Epidemiology, and End Results registry.

RESULTS

FEA was identified in 282 women (2.4%); 130 had associated AH (46%) and 152 (54%) were classified as having proliferative disease without atypia (PDWA). With median follow-up of 16.8 years, the SIR for breast cancer in patients with AH plus FEA was 4.74 (95% confidence interval [95% CI], 3.17-6.81) versus 4.23 (95% CI, 3.44-5.13) for those with AH without FEA (P = .59). The SIR for patients with PDWA plus FEA was 2.04 (95% CI, 1.23-3.19) versus 1.90 (95% CI, 1.72-2.09) for patients with PDWA without FEA (P = .76).

CONCLUSIONS

FEA is an uncommon finding in women with benign breast disease. FEA does not appear to convey an independent risk of breast cancer beyond that of the associated PDWA or AH.

Columnar cell lesions on breast needle biopsies: is surgical excision necessary? A systematic review

OBJECTIVE

This systematic review was conducted to provide treatment recommendations for patients with a diagnosis of columnar cell lesions (CCLs) in a breast core needle biopsy (CNB).

BACKGROUND

CCLs are putative breast cancer precursors and are often associated with (in situ) carcinoma in excision specimens. Although several studies reported on the progression risk and underestimation rate of a CNB diagnosis of CCL, there is no consensus regarding optimal clinical management in this context.

METHODS

We searched MEDLINE, Embase, and Cochrane databases from 1990 to October 2010 for studies on patients with a CNB diagnosis of CCL without atypia, CCL with atypia and atypical ductal hyperplasia associated with CCL followed by surgical excision or clinical follow up.

RESULTS

Of 1759 selected articles, 24 were included in this review. The pooled underestimation risks for (in situ) carcinoma were as follow: CCL without atypia 1.5% (95% confidence interval [CI] 0.6%-4%), CCL with atypia 9% (95% CI: 5%-14%), and atypical ductal hyperplasia associated with CCL 20% (95% CI: 13%-28%), based on the whole groups of patients with a CNB. Studies including CCLs with long-term clinical follow-up showed a trend toward a limited elevated breast cancer risk.

CONCLUSIONS

On the basis of the (in situ) carcinoma underestimation rates of patients with a CNB diagnosis of CCL with atypia and atypical ductal hyperplasia associated with CCL, surgical excision should be considered. For CCL without atypia, more studies with a long-term follow-up are required, but so far, surgical excision biopsy does not seem to be necessary.

Digital mammography: more microcalcifications, more columnar cell lesions without atypia

The incidence of columnar cell lesions in breast core needle biopsies since full-field digital mammography in comparison with screen-filmed mammography was analyzed. As tiny microcalcifications characterize columnar cell lesions at mammography, we hypothesized that more columnar cell lesions are diagnosed since full-field digital mammography due to its higher sensitivity for microcalcifications. In all, 3437 breast core needle biopsies performed in three hospitals and resulting from in total 55 159 mammographies were revised: 1424 taken in the screen-filmed mammography and 2013 in the full-field digital mammography period. Between the screen-filmed mammography and full-field digital mammography periods, we compared the proportion of mammographies that led to core needle biopsies, the mammographic indication for core needle biopsies (density, microcalcifications, or both) and the proportion of columnar cell lesions with or without atypia. The columnar cell lesions were graded according to Schnitt, and we included atypical ductal hyperplasia arising in the context of columnar cell lesions. Proportions were compared using χ(2) tests and prevalence ratios were adjusted for age and hospital. We found that more core needle biopsies per mammogram were taken in the full-field digital mammography period (7.6%) compared with the screen-filmed mammography period (5.0%, P<0.0001). Microcalcifications were more often diagnosed with full-field digital mammography than with screen-filmed mammography (adjusted prevalence ratio: 1.14, confidence interval 95%: 1.01-1.28). Core needle biopsies from the full-field digital mammography era showed more columnar cell lesions (10.8%) than those from the screen-filmed mammography era (4.9%; adjusted prevalence ratio: 1.93, confidence interval 95%: 1.48-2.51), particularly due to more columnar cell lesions without atypia (8.2% respectively 2.8%) while the proportion of columnar cell lesions with atypia remained nearly constant (2.0 vs 2.6%). In conclusion, since the implementation of full-field digital mammography, more microcalcifications are seen at mammography, more often resulting in core needle biopsies, which especially yields more columnar cell lesions without atypia.

Progression risk of columnar cell lesions of the breast diagnosed in core needle biopsies

Columnar cell lesions (CCLs) of the breast are recognized as putative precursor lesions of invasive carcinoma, but their management remains controversial. We therefore conducted a retrospective study on 311 CCLs, diagnosed in 4,164 14-gauge core needle biopsies (CNB): 221 CCLs without atypia (CCL), 69 with atypia (CCL-A), and 21 atypical ductal hyperplasias originating in CCL (ADH-CCL). Two groups were identified: "immediate treatment" group undergoing excision within four months after the CNB diagnosis of CCL (N = 52) and the "wait-and-see" group followed up to 8 years (median 3.5 years, N = 259). In 7 of 31 women (22.5%, 1 CCL, 4 CCL-A, 2 ADH-CCL) who underwent immediate surgical excision and were initially biopsied for microcalcifications, ductal carcinoma in situ (DCIS) was present and in 2/31 women (6.5%, 1 CCL, 1 CCL-A) invasive carcinoma. In 2/21 excisions (9.5%, 1 CCL, 1 CCL-A) initially biopsied for a density, DCIS was present and invasive carcinoma in 5/21 excisions (23.8%, 2 CCL, 3 CCL-A). In the wait-and-see group, 9/259 women (3.5%) developed invasive carcinoma, 6 ipsi, and 3 contralaterally. Progression risks of CCL-A and ADH-CCL were 18% and 22%,versus 2% for CCL without atypia (p < 0.001). In conclusion, CCL-A or ADH-CCL in a CNB were associated with a high risk of DCIS/invasive carcinoma in immediate surgical excision biopsies. The 8-years progression risks for CCL-A and ADH-CCL were around 20%. This illustrates that an atypical CCL in a CNB may signal the presence of concurrent lesions or development of advanced lesions in future and may justify ("mini") surgical excision.

Monomorphic epithelial proliferations of the breast: a possible precursor lesion associated with ipsilateral breast failure after breast conserving therapy in patients with negative lumpectomy margins

BACKGROUND

It is generally believed that ipsilateral breast failures (IBFs) after breast-conserving therapy (BCT) develop from incompletely eradicated carcinoma. We previously suggested that monomorphic epithelial proliferations (MEPs) in the breast may be a pool of partially transformed clones from which breast carcinomas can arise and that radiation therapy (RT) may also reduce the risk of IBF by eradicating MEPs. We examined salvage mastectomy specimens in patients experiencing an IBF to define the relationship between MEPs and IBFs and an additional potential mechanism for IBF risk reduction by RT.

METHODS AND MATERIALS

The location, number, and distribution of radiation changes and MEPs relative to 51 IBFs were mapped in salvage mastectomy specimens from BCT patients with adequately excised, initial carcinomas (negative lumpectomy margins).

RESULTS

All 51 salvage mastectomies had diffuse, late radiation changes. None had active fibrocystic lesions. MEPs were predominantly located in the immediate vicinity of the IBFs. A mean of 39% of MEP cases were located within the IBF, 46% were located within 2 cm of the IBF, and 14% were 2-3 cm from the IBF.

CONCLUSIONS

MEPs appear to be a pool of partially transformed precursor lesions that can give rise to ductal carcinoma in situ and invasive carcinomas (CAs). Many IBFs may arise from MEPs that reemerge after RT. Radiation may also reduce IBF risk after BCT (including in patients with negative margins) by primarily eradicating MEPs.

The molecular pathology of breast cancer progression

The current model of human breast cancer progression proposes a linear multi-step process which initiates as flat epithelial atypia (FEA), progresses to atypical ductal hyperplasia (ADH), evolves into DCIS and culminates in the potentially lethal stage of invasive ductal carcinoma. For several decades a major challenge to human breast cancer research has been the identification of the molecular alterations associated with the different stages of breast cancer progression. Until recently, progress in attaining this goal has been hampered by technical limitations associated with applying advanced molecular technologies to the microscopic preinvasive stages of breast tumorigenesis. Recent advances in comprehensive, high-throughput genetic, transcriptomic and epigenetic technologies in combination with advanced microdissection and ex vivo isolation techniques have provided for a more complete understanding of the complex molecular genetic and molecular biological inter-relationships of the different stages of human breast cancer evolution. Here we review the molecular biological data suggesting that breast cancer develops and evolves along two distinct molecular genetic pathways. We also briefly review gene expression and epigenetic data that support the view of the tumour microenvironment as an important co-conspirator rather than a passive bystander during human breast tumorigenesis.

Preinvasive breast cancer

Preinvasive breast cancer accounts for approximately one-third of all newly diagnosed breast cancer cases in the United States and constitutes a spectrum of neoplastic lesions with varying degrees of differentiation and clinical behavior. High-throughput genetic, epigenetic, and gene-expression analyses have enhanced our understanding of the relationship of these early neoplastic lesions to normal breast tissue, and they strongly suggest that preinvasive breast cancer develops and evolves along two distinct molecular genetic and biological pathways that correlate with tumor grade. Although unique epigenetic and gene-expression changes are not observed in the tumor epithelial compartment during the transition from preinvasive to invasive disease, distinct molecular alterations are observed in the tumor-stromal and myoepithelial cells. This suggests that the stromal and myoepithelial microenvironment of preinvasive breast cancer actively participates in the transition from preinvasive to invasive disease. An improved understanding of the transition from preinvasive to invasive breast cancer will pave the way for novel preventative and therapeutic strategies.

Flat Ductal Intraepithelial Neoplasia of the Breast: A Review of Diagnostic Criteria, Differential Diagnoses, Molecular-Genetic Findings, and Clinical Relevance—It Is Time to Appreciate the Azzopardi Concept!

Context.—More than 25 years ago, John G. Azzopardi described a distinctive intraepithelial neoplastic breast lesion, which he designated “clinging carcinoma in situ”; he considered it as another variant of ductal carcinoma in situ, an early lesion that can easily be missed because the changes are mainly cytologic rather than architectural. The lesion remained widely unrecognized and/or ignored until recent years when its neoplastic nature was confirmed at the molecular-genetic level.

Objective.—To deal with historical aspects of the evolving concept of “clinging” and to focus on several important issues such as characteristic morphologic features with particular attention to the diagnostic criteria and differential diagnoses, recent molecular-genetic findings, appropriate terminology and classification, as well as the significance of this type of lesion for both surgical pathologists and clinicians.

Data Sources.—A thorough search of the literature was performed and publications using a variety of designations including “clinging carcinoma in situ,” “flat epithelial atypia,” “ductal intraepithelial neoplasia-flat type,” “atypical cystic lobules,” “columnar cell change with atypia,” “columnar cell hyperplasia with or without atypia,” “columnar alteration with prominent apical snouts and secretion,” and so forth were reviewed.

Conclusions.—This distinctive lesion represents one of the earliest morphologically recognizable neoplastic alterations of the breast that is commonly associated with mammographically suspicious microcalcifications. It is characterized by mildly to severely atypical cells simply replacing the single layer of native epithelial cells in a flat fashion without appreciable proliferation; tufting, intraluminal bridging, micropapillary structures, and so forth are typically absent or very focal and minimal, if present at all. Based on the degree of cytologic atypia, low- and high-grade flat ductal intraepithelial neoplasia need to be separated. Although additional studies are needed to better understand the clinical significance of flat ductal intraepithelial neoplasia, several lines of evidence strongly support the concept of clinging. Indeed, as pointed out by Azzopardi, surgical pathologists need to pay more attention to the cytologic alterations of the breast lesions by analyzing the involved cell populations using high-power magnification.

Columnar cell lesions of the breast: an update and significance on core biopsy

Columnar cell lesions of the breast refer to the morphological spectrum of alterations of the epithelial lining of variably dilated acini of the terminal duct lobular unit (TDLU), often related to secretions and calcifications. After decades of varied terminologies, the term of 'flat epithelial atypia' by the World Health Organization (WHO) consensus group encompasses the part of the spectrum where columnar cell change or columnar cell hyperplasia acquires low grade cytological atypia, merging with atypical ductal hyperplasia and low grade ductal carcinoma in situ. Its association with low grade invasive carcinoma and lobular neoplasia, whether by proximity to these lesions, or by similar molecular expressions, has prompted greater scrutiny into its clinical significance. Although recent literature attempts to refine the term 'flat epithelial atypia', the applicability of its morphological criteria in routine diagnostic practice remains to be seen, and interobserver variability is highly possible. This poses even greater challenges especially in limited samples of breast tissue, such as in core biopsies, for pre-operative decision-making. The purpose of this review is to elucidate evolving clinical and diagnostically relevant principles that surround and influence the significance of this still controversial entity, especially when discovered on core biopsy in the initial phase of breast diagnosis and management.

Estrogen effects on epithelial proliferation and benign proliferative lesions in the postmenopausal primate mammary gland

Proliferative lesions of the mammary gland are risk markers and potential precursors for the development of breast cancer in postmenopausal women. In this study we evaluated mammary epithelial proliferation and proliferative lesions in a group of 63 aged postmenopausal macaques randomized by social group to receive one of three experimental diets for 8 months: (1) control; (2) control with 17beta-estradiol (E2) at the human equivalent dose of 1.0 mg per day; and (3) control with the soy phytoestrogen equol (EQ) at the human equivalent dose of 105 mg per day. In normal mammary epithelium, treatment with E2 but not EQ resulted in greater proliferation, epithelial area, and progesterone receptor expression (P<0.05 for all). Mammary lesions included columnar cell change (26/63), columnar cell hyperplasia with and without atypia (13/63), atypical ductal hyperplasia (6/63), and atypical lobular hyperplasia (3/63). Lesions were most common within terminal ductal lobular units. The prevalence of columnar cell hyperplasia (total and atypical cases) was higher in animals treated with E2 compared to control (P<0.05 for both). Compared to normal mammary epithelium, columnar cell lesions (CCLs) showed greater constitutive expression of estrogen receptor-alpha across all groups (P<0.001) and greater expression of progesterone receptor in response to E2 (P<0.01). Independent of treatment, animals with CCLs on histology had greater gene expression of estrogen receptor-alpha and markers of estrogen receptor activity (trefoil factor 1) and proliferation (gene for Ki67 antigen) at a site contralateral to the CCL (P<0.05 for all). These findings demonstrate that the terminal ductal lobular units of the postmenopausal mammary gland contain morphologically distinct cell populations that may hyperrespond to E2 exposure, resulting in specific types of hyperplastic lesions.

Flat epithelial atypia of the breast

Flat epithelial atypia is a presumably neoplastic alteration of terminal duct-lobular units that is characterized by the replacement of the native luminal epithelium by ductal cells demonstrating low-grade cytologic atypia. The atypical cells maintain a "flat" pattern of growth without evidence of architectural atypicality. Morphologic, immunohistochemical, and molecular investigations support that flat epithelial atypia represents an early step in the evolution of low-grade ductal carcinomas. It is frequently seen in association with atypical ductal hyperplasia, low-grade ductal carcinoma in situ, invasive tubular carcinoma, and lobular neoplasia. The risk for subsequent breast carcinoma remains to be defined, but flat epithelial atypia likely represents a nonobligate precursor with an extended time course to progression. Certain benign alterations may superficially mimic its appearance; careful attention to cytologic and architectural characteristics can help one distinguish these unrelated entities from flat epithelial atypia.

A case of solitary intraductal papilloma of the breast coexisting with ductal carcinoma in situ (DCIS)

A 54-year-old woman was referred to this institution because of spontaneous bloody discharge from the nipple of her left breast in July 2003. Physical examination revealed no mass, but minimal pressure on the mammary gland exuded a bloody discharge from the nipple. No lymph node swelling was recognized in the axillary or subclavicular regions. Mammography and magnetic resonance imaging revealed mastopathy. Ultrasonography on the immersion method demonstrated a dilated duct with an irregular, solid, hypoechoic mass immediately behind the nipple. Fine-needle aspiration cytology showed the mass to be an intraductal tumor. Carcinoembryonic antigen (CEA) concentration of the nipple discharge was 400 ng/ml. Preoperatively, she was diagnosed as intraductal solitary papilloma, and endoscope-assisted microdochectomy was carried out under general anesthesia. The tumor was 10.5-10.6 mm in diameter and had developed from the posterior wall of the duct adjacent to the nipple. The tumor contained a small solid area in which a two-cell layer of epithelium was missing, and thus solitary papilloma coexisting with ductal carcinoma in situ (DCIS) was diagnosed. Solitary intraductal papilloma coexisting with carcinoma is rare; cases of DCIS are exceptionally rare. Follow-up for 3 years has revealed no evidence of recurrence.

Cytologic diagnosis of columnar-cell lesions of the breast

This study describes the cytologic features of breast columnar-cell lesions (CCLs) and determines whether these lesions can be diagnosed by fine-needle aspiration. We present ten cases of biopsy-proven CCL with prior fine-needle aspiration material and discuss the spectrum of changes, as well as features important in the cytologic distinction of CCL from diagnostic mimics. CCLs were characterized by flat sheets of cells with enlarged nuclei, distinct cell borders, and finely granular cytoplasm. Cytologic atypia ranged from minimal to severe, and many cases (8/10) exhibited a paucity of myoepithelial cells. CCL showed significant cytologic overlap with papillary neoplasms and well-differentiated adenocarcinomas. The prospective diagnosis of CCL cannot reliably be made by fine-needle aspiration. However, it is important to recognize the range of cytologic atypia that can be seen with CCL to avoid an overdiagnosis of malignancy.

Melatonin and estrogen in breast cyst fluids

Increased breast cancer risks have been reported among women with gross cystic breast disease (GCBD), although the mechanism for this increase remains unexplained. Relationships between GCBD characteristics, breast cancer risk factors, and the biochemical composition and growth properties of 142 breast cyst fluid (BCF) samples were studied among 93 women with GCBD. Concentrations of melatonin, estrogen (17-beta-estradiol), dehydroepiandrosterone-sulfate (DHEA-S), epidermal growth factor (EGF), transforming growth factor beta (TGF-B1 and TGF-B2), sodium (Na), and potassium (K) were quantified in BCF samples, and human breast cancer cells (MCF-7) were treated with BCF in vitro. Patients were grouped according to BCF Na:K ratios previously linked with increased breast cancer risks (Na:K </= 3, Type 1), and mean concentrations of BCF constituents were compared with low risk (Na:K > 3, Type 2) and mixed cyst groups. Women with larger and more frequently occurring cysts had higher BCF estrogen and DHEA-S, and lower TGF-B1 levels. Women with Type 1 cysts had elevated BCF melatonin, estrogen, DHEA-S, and EGF, and lower concentrations of TGF-B2 compared to women with Type 2 cysts. BCF generally inhibited cell growth relative to serum-treated controls, consistent with previous studies. Melatonin and estrogen in BCF independently predicted growth inhibition and stimulation, respectively. Biological monitoring of BCF may help identify women with GCBD at greatest risk for breast cancer development.

Flache epitheliale Atypie und andere Zylinderzellläsionen der Brust

Columnar cell lesions are being increasingly identified in specimens excised for mammographically suspect microcalcifications. The entity of flat epithelial neoplasia remains a challenge for surgical pathologists due to its uncertain biological and clinical significance, inconsistent nomenclature, lack of prognostic data and the often unobtrusive and easily overlooked histological findings. This review aims to summarize our experience and the currently available literature on this topic, and will lead to a better understanding of this lesion. Because of its putative role as a precursor lesion and its many similarities to atypical ductal hyperplasia or ductal carcinoma in situ, differentiation from these lesions on the one hand and from columnar cell lesions without atypia on the other, is of importance and should result in different therapeutic recommendations depending on its presence in excisional or core needle biopsies.

Biology of Ductal Carcinoma in Situ Classification Based on Biologic Potential

Incidence of ductal carcinoma in situ (DCIS) has increased significantly during the last decade, comprising almost 20% of all breast cancers diagnosed today. DCIS is composed of malignant breast duct epithelial cells that have clonally proliferated and accumulated within the mammary duct lumen. It comprises a group of heterogeneous tumors with varying biologic behavior rendering its classification and management challenging. By definition, DCIS does not invade through the basement membrane; it is a preinvasive malignancy and systemic disease is nonexistent. The basis of treatment is to prevent progression into an invasive cancer such as ductal carcinoma. Most current DCIS classification schemes do not predict its potential to progress to invasive disease. In this review the natural history of DCIS, as it relates to its biologic potential to progress to invasive disease, is summarized, and a broad classification system that may provide a guideline for patient management is proposed.

Apocrine cysts of the breast: biomarkers, origin, enlargement, and relation with cancer phenotype

Up to one-third of women aged 30-50 years have cysts in their breasts and are presumed to be at increased risk of developing breast cancer. Here we present an extensive proteomic and immunohistochemistry (IHC) study of breast apocrine cystic lesions aimed at generating specific biomarkers and elucidating the relationship, if existent, of apocrine cysts with cancer phenotype. To this end we compared the expression profiles of apocrine macrocysts obtained from mastectomies from high risk cancer patients with those of cancerous and non-malignant mammary tissue biopsies collected from the same patients. We identified two biomarkers, 15-hydroxyprostaglandin dehydrogenase and 3-hydroxymethylglutaryl-CoA reductase, that were expressed specifically by apocrine type I cysts as well as by apocrine metaplastic cells in type II microcysts, terminal ducts, and intraductal papillary lesions. No expression of these markers was observed in non-malignant terminal ductal lobular units, type II flat cysts, stroma cells, or fat tissue as judged by IHC analysis of matched non-malignant tissue samples collected from 93 high risk patients enrolled in our cancer program. IHC analysis of the corresponding 93 primary tumors indicated that most apocrine changes have little intrinsic malignant potential, although some may progress to invasive apocrine cancer. None of the apocrine lesions examined, however, seemed to be a precursor of invasive ductal carcinomas, which accounted for 81% of the tumors analyzed. Our studies also provided some insight into the origin, development, and enlargement of apocrine cysts in mammary tissue. The successful identification of differentially expressed proteins that characterize specific steps in the progression from early benign lesions to apocrine cancer opens a window of opportunity for designing and testing new approaches for pharmacological intervention, not only in a therapeutic setting but also for chemoprevention, to inhibit cyst development as both 15-hydroxyprostaglandin dehydrogenase and 3-hydroxymethylglutaryl-CoA reductase are currently being targeted for chemoprevention strategies in various malignancies.

Flat epithelial atypia: concepts and controversies of an intraductal lesion of the breast

Image-guided biopsies of the breast play an integral role in the diagnostic evaluation of mammographically detected calcifications. Apart from cancer, on these biopsies we are increasingly recognising a hitherto poorly categorised group of benign to atypical entities collectively known as columnar cell lesions. A variant of this theme is flat epithelial atypia, a columnar lesion characterised by mildly atypical epithelial cells. There is emerging evidence to suggest that flat epithelial atypia may represent a precursor of or the earliest morphologically recognisable form of low-grade ductal carcinoma in situ. In addition, these lesions are often associated with tubular carcinomas and lobular neoplasia. This article reviews the current concepts and controversies surrounding flat epithelial atypia, with special emphasis on the biology, histological and clinical features. Potential diagnostic challenges faced by pathologists in the evaluation of these atypical columnar lesions are also discussed.

Immunohistochemical analysis of 14-3-3 sigma and related proteins in hyperplastic and neoplastic breast lesions, with particular reference to early carcinogenesis

In order to confirm the role of 14-3-3 sigma (sigma) as a tumor suppressor in breast carcinogenesis, we have studied the expression of 14-3-3sigma immunohistochemically in usual ductal hyperplasia (UDH), ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) breast lesions. Immunostaining for estrogen receptor alpha (ERalpha), p53 and estrogen-responsive RING finger protein (Efp) was also carried out. Immunohistochemically, expression of 14-3-3sigma was seen in 92% UDH lesions and gradually decreased from 65% in DCIS to 23% in IDC. The expression of ERalpha decreased gradually from UDH to DCIS to IDC, while p53 showed an inverse staining pattern to that of ERalpha. The expression of Efp showed no significant difference among the three breast lesions. Hence, the present immunohistochemical study confirmed 14-3-3sigma as a tumor suppressor in breast carcinogenesis. A similar immunohistochemical analysis was then carried out on columnar cell hyperplasia with atypia (CCHA), in which the expression pattern of tumor suppressor 14-3-3sigma, ERalpha and p53 suggested that it might be possible that CCHA is a precancerous lesion.

Columnar cell lesions: current classification and controversies

"Columnar cell lesions" is a general descriptive term referring to disparate lesions having in common cells with a columnar configuration but not necessarily identical histologic or biologic characteristics. Within this large category, a group of lesions having in common a population of atypical cells (frequently columnar shaped) is emerging as early neoplastic lesions. This article reviews the histological features, differential diagnosis, associated lesions, biologic potential, clinical significance, and management of atypical columnar cell lesions.

Microcysts and breast cancer: a study of biological markers in archival biopsy material

Breast cysts are associated with an increased risk of breast cancer. Some biomarkers such as estrogen receptor alpha (ERa), progesterone receptor (PR), and cyclin D1, show similar patterns of expression in epithelial cells lining breast cysts as malignant epithelial cells in local and invasive ductal breast cancer. We have attempted to answer two questions: (1) Do epithelial cells lining breast microcysts (cysts which can only be seen with a microscope) express biomarkers in a similar pattern to breast ductal carcinoma in situ and invasive ductal carcinoma? (2) Are breast microcysts precursors of breast cancer or are they part of normal involution of the breast? Seventy two archival open breast biopsy specimens of ductal carcinoma in situ and invasive ductal carcinoma and 32 normal breast biopsies from Australian women who had breast reduction surgery were selected from hospital archives. All specimens were analysed by standard immunohistochemistry for ERa, PR, cyclin D1, bcl-2, p53 and erbB-2 expression. In the same specimens, the pattern of high biomarker expression was very similar for all the above biomarkers in epithelial cells lining microcysts and in both ductal carcinoma in situ and invasive ductal carcinoma c. ErbB-2 was not expressed in normal control specimens. ErbB-2 was expressed in the same specimens in an increasing proportion of normal breast acini, microcysts and cancer cells in 36% of specimens with breast cancer. An apparent progression was observed from normal breast acini, to proliferation of epithelial cells in microcysts, ductal carcinoma in situ and invasive ductal carcinoma in the same specimen. When these findings are considered with other reports we conclude: (1) that epithelial cells lining breast cysts highly express biomarkers in a similar pattern to ductal carcinoma in situ and invasive ductal carcinoma; (2) that some microcysts are not part of normal involution of the breast and in some women may be part of the transition from normal to cancer.