[Clinical analysis of seven patients with occult breast cancer and literature reviews]

BACKGROUND AND OBJECTIVE

Occult breast cancer is a kind of specific seldom clinically seen breast cancer. This study was designed to investigate the diagnosis and treatment of the patients with breast cancer.

METHODS

Retrospective study was conducted in 7 cases of occult breast cancer from May 1990 to May 2001.

RESULTS

All cases were female and account for 0.59% of the total breast cancer treated in the same period. Axillary node enlargement was presented as first sign and no breast mass was palpable in physical examination. Fine needle aspiration or excisional biopsy revealed metastatic adenocarcinoma before surgery. All cases were taken mammography and 1 case was suspicious of malignancy. 3 cases were taken ultrasonography and 1 case was suspicious of malignancy. 5 cases underwent radical mastectomy and 2 cases underwent modified radical mastectomy. Pathological examination of the removed specimen found the primary breast cancer leison in 4 case and showed infiltrative carcinoma in 3 cases and intraductal carcinoma in 1 case. After surgery, 2 cases received radiotherapy plus chemotherapy, 5 case received chemotherapy and 4 case received tamoxifen therapy. All case were still alive and 3 cases survived over 54 months and 1 case survived for 7 years.

CONCLUSION

Occult breast cancer should be considered when axillary lymph node is enlarged in female. Fine needle aspiration and excisional biopsy are helpful in pathologic diagnosis preoperatively. Mammography and ultrasonography have low sensitivity in identifying primary tumor. Radical or modified radical mastectomy with adjuvant radiotherapy and chemotherapy is a suitable choice for the patients with occult breast cancer and the prognosis is superior or similar to those patients who with palpable mass both in breast and axillary.

Can true papillary neoplasms of breast and their mimickers be accurately classified by cytology?

BACKGROUND

The cytologic accuracy in assessing malignancy in papillary breast neoplasms (PBNs) is controversial. This is further complicated by overlapping features observed in other breast lesions that produce papillary-like tissue fragments.

METHODS

The authors reviewed 22 fine-needle aspirates (FNAs) from histologically proven papillary neoplasms: papillary carcinoma (PCA; 10 aspirates) and intraductal papilloma (IDP; 12 aspirates). They also reviewed 8 FNAs in which a papillary neoplasm was suggested by cytology but not confirmed by follow-up biopsy: fibroadenoma (6), mucinous carcinoma (1), and cribriform ductal carcinoma in situ (1).

RESULTS

Papillary carcinoma can be distinguished from IDP by the higher cellularity, more complex papillae with thin disorganized fronds, mild to moderate nuclear atypia, and prominent dissociation with many single papillae. Fibrovascular cores (FVCs) were more common in PCA than IDP in which detached fibrous tissue fragments were frequently seen. Atypical IDP exhibited features intermediate between PCA and IDP. Apocrine metaplasia was variably present in IDP, atypical IDP, and fibroadenoma but absent in all carcinomas. Intraductal papilloma can be distinguished from fibroadenoma by their broad ruffled branches, scalloped borders, and tiny tongue-like projections. True papillae were commonly covered by tall columnar cells. Myoepithelial cells were few in IDP but were numerous in fibroadenoma. The epithelial fragments in nonpapillary lesions presented as cellular spheres and/or complex sheets with finger-like projections but lacked FVCs and columnar cells.

CONCLUSIONS

Papillary breast neoplasms can be accurately classified by cytology. Closer evaluation of the tissue fragments architecture and the background can help in separating PBN from their mimics.

The treatment of ductal carcinoma in situ of the breast

As screening mammography has become more frequently used to screen asvmptomatic women, the diagnosis of ductal carcrinoma in situ (DCIS) has become commonplace. Its treatment remains contentious, ranging from mastectomy to local excision alone. The goal of treatment for DCIS is breast conservation, however, as many as 25% of women with this diagnosis may require mastectomy. Although no clear selection criteria have been adopted to subdivide patients into groups best treated by either mastectomy or local excision with or without radiation therapy, many patients with DCIS are candidates for local excision alone, if the biology of the disease is favorable, the size is small, and the margins are negative. Radiation therapy added to local excision decreases the likelihood of recurrence; however, if there is recurrence when first radiation is employed, the patient's only remaining choice often is mastectomy.

Nuclear chromatin characteristics of breast solid pattern ductal carcinoma in situ

OBJECTIVE

To characterize nuclei from breast solid pattern ductal carcinoma in situ (DCIS) by their karyometric features and to search for the presence of statistically significantly different subsets of nuclei.

STUDY DESIGN

One hundred nuclei from each of 6 normal, 13 solid DCIS, (9 low and intermediate grade and 4 high grade DCIS) histopathologic samples of breast tissue were digitally recorded. Karyometric features were computed and subjected to a nonsupervised learning algorithm (P-index) to identify significantly different subgroups.

RESULTS

Nuclei in low grade lesions displayed a diploid/near diploid pattern, while the majority of intermediate grade lesions fell into a range beyond 5N. The high grade lesions showed substantial genomic instability and represented three statistically different subsets or phenotypes.

CONCLUSION

There is a progression of nuclear abnormality from low grade to high grade DCIS. The nuclei from high grade DCIS form a heterogeneous set that represents three phenotypes. One of these phenotypes shows a nuclear chromatin pattern that more closely resembles poorly differentiated, infiltrating disease. The observation of such a phenotype may have prognostic implications.

Pathology of ductal carcinoma in situ of the breast: a heterogeneous entity in need of greater understanding

Breast cancer is the commonest malignancy among Singapore women. Ductal carcinoma in situ (DCIS) is the putative precursor of the majority of invasive breast cancers, and its incidence has increased dramatically with mammographic screening. It is a heterogeneous disease--radiologically, pathologically and biologically. While the diagnosis of breast cancer in its pre-invasive phase, DCIS, allows the likelihood of cure with effective therapy, issues that surround its pathological heterogeneity are often not fully understood nor recognised. In this paper, the pathology and natural history of breast DCIS are reviewed; with emphasis on pathological classification schemes that attempt to predict recurrent disease or progression to invasive cancer. The potential role of biological markers is also evaluated. Atypical ductal hyperplasia, a lesion that is often difficult to distinguish from low grade DCIS; the significance and definition of microinvasion; and the value of fine needle aspiration cytology in DCIS are discussed. In addition, pathologic-radiologic correlations of local screen-detected cases of breast DCIS are presented. Awareness of the pathological parameters that impact on the biological behaviour of breast DCIS will enable appropriate management strategies; avoiding overtreatment in biologically indolent disease, while optimising adequate therapy for aggressive lesions.

Immunohistochemical analysis on biological markers in ductal carcinoma in situ of the breast

BACKGROUND

The increasing use of mammographic screening has led to an increased detection of ductal carcinoma in situ (DCIS) of the breast. The detailed biological characteristics of DCIS and a new classification of DCIS based on these characteristics are needed.

METHODS

Immunohistochemical studies were performed to assess the expression of c-erbB-2 (ErbB-2), estrogen receptor (ER), p53 and proliferative activity (Ki-67) in 65 patients with pure DCIS and 60 with invasive ductal carcinoma (IDC). We classified pure DCIS tumors using three classifications, the architectural, Nottingham, and Van Nuys classifications.

RESULTS

ErbB-2, ER and p53 staining was positive in 34%, 66% and 21% of patients with DCIS, respectively, and 58%, 42% and 33% in patients with IDC, respectively. Ki-67 stained positively in 1.5% of patients with DCIS and 11.2% of patients with IDC. The comedo type showed a high rate of positive ErbB-2 and p53 staining. The cribriform and papillary types showed a high rate of positive ER staining. Under the Van Nuys classification, ErbB-2, p53 and Ki-67 expression were highest in the group with high nuclear grade and lowest in the group with non-high nuclear grade without necrosis.

CONCLUSION

Although the biological markers of IDC tended to suggest aggressive behavior more so than those of DCIS, these differences were based on the histological sub-type, comedo or non-comedo. The Van Nuys classification best defined the subgroups of DCIS with a distinct expression pattern of biological markers, and the best candidates for breast-conserving surgery.

Percutaneous imaging-guided core breast biopsy: 5 years' experience in a community hospital

OBJECTIVE

This study reports the results of a percutaneous imaging-guided core breast biopsy program in a community hospital.

MATERIALS AND METHODS

We reviewed the prospectively collected results of our imaging-guided core biopsy program during its first 5 years (1994-1998). A total of 1333 lesions (94% of which were Breast Imaging Reporting and Data System (BI-RADS) assessment category 4) were sampled in 1183 patients. Patients with BI-RADS assessment category 5 lesions were referred to surgeons. Stereotactic guidance was used for the core biopsy of 506 lesions, and sonography was used to guide the predominantly 16-gauge needle core biopsy of 827 solid masses.

RESULTS

One hundred forty-seven cancers were diagnosed in 1333 biopsies, resulting in a positive yield of 11%. Of 1020 patients with benign, concordant core biopsy results, 981 (96%) had at least one follow-up imaging examination within 36 months of the biopsy. Nineteen (2%) of these 1020 patients had a suspicious change at follow-up; 18 of these patients underwent surgical excision with benign findings. No cancers were found at imaging follow-up or by tumor registry linkage. All malignant core biopsy results were confirmed as malignant at surgical excision (positive predictive value 100%). Twenty-two patients with atypical ductal hyperplasia at core biopsy had subsequent surgery, and 12 (55%) of them were found to have cancer at surgery.

CONCLUSION

An imaging-guided core biopsy program, developed and implemented by a small group of radiologists in a community hospital, can achieve successful results and provide an important service to patients and a cost-effective alternative to surgical biopsy. Our program emphasized sonographic guidance and achieved high follow-up compliance.

Fine-needle aspiration cytology of the breast: Invasive vs. in situ carcinoma

The surgical management of invasive breast carcinoma differs from that of in situ disease. Invasive carcinoma necessitates axillary lymph node dissection, a procedure that has associated morbidity. We studied 80 cases (66 invasive, 14 in situ) of breast carcinoma that had a histological diagnosis and a preoperative fine-needle aspirate. All slides were reviewed, with 17 cytologic features assessed. We found that six of these features showed a statistically significant difference between the invasive and in situ cases. These were infiltration of fat or stroma by malignant cells (72% of invasive cases demonstrated this feature, but it was not present in any of the in situ cases, P = 0.0002), the presence of myoepithelial cells overlying clusters of tumor cells (seen in 86% of in situ tumors and 7% of invasive cases, P < 0.00001), calcification (present in 71% of in situ and 15% of the invasive group, P = 0.001), foamy macrophages (noted in 64% of in situ tumors and 16% of invasive carcinomas, P = 0.0007), intracytoplasmic vacuoles (seen in 50% of invasive cases and 21% of in situ lesions, P = 0.08), and tubules (present in 30% of invasive and 7% of in situ tumors, P = 0.10). We demonstrate that invasion can be suggested in fine-needle aspirates of carcinomas, provided that true infiltration of fibrofatty connective tissue by neoplastic cells is present. In situ disease has characteristic features, but the presence of invasion cannot be excluded, even in the presence of stromal or adipose tissue fragments without tumor infiltration.

Pathobiologic findings in DCIS of the breast: morphologic features, angiogenesis, HER-2/neu and hormone receptors

With the increasing incidence of ductal carcinoma in situ (DCIS) of the breast and its relationship to invasive breast carcinoma, it is important to understand the biology of this entity. We report on a hospital-based survey of 219 case subjects with DCIS of the breast without associated invasive carcinoma diagnosed between 1982 and 1994. The cases of DCIS were analyzed for architectural type, size, nuclear grade, necrosis, calcification, periductal fibrosis, neovascularization, estrogen receptor (ER), progesterone receptor (PR), and HER-2/neu expression. Periductal neovascularization was associated with tumor size, microcalcifications, periductal fibrosis, and HER-2/neu overexpression. Expression of ER and PR was observed in 60 and 62% of the cases, respectively, and HER-2/neu overexpression in 28% of the cases. ER and PR expression were both inversely associated with comedo histology and nuclear grade. HER-2/neu overexpression was positively associated with comedo histology, high nuclear grade, and periductal neovascularization and was inversely correlated with both ER and PR expression. High nuclear grade was positively associated with comedocarcinoma, necrosis, microcalcification, and periductal fibrosis. The role of these molecular/pathologic markers in the biology of DCIS and their potential clinical implications are discussed.

Amplification of growth regulatory genes in intraductal breast cancer is associated with higher nuclear grade but not with the progression to invasiveness

Ductal carcinoma in situ (DCIS), as an identifiable progenitor lesion of invasive breast cancer, represents a morphologically, biologically, and prognostically heterogeneous disease. It is not clear which molecular mechanisms are involved in progression to infiltrative growth. In this study, 83 DCIS classified according to the Van Nuys grading scheme were examined for amplification of growth regulatory genes that have been found to be amplified in invasive breast cancer (c-erbB2, topoisomerase IIalpha, c-myc, and cyclinD1 genes). Exact quantification of gene amplification was enabled by a combination of laser microdissection of paraffin-embedded tissue with real-time PCR. In DCIS, gene amplifications of all tested genes were found. The most frequently amplified gene was c-erbB2 found in 21 of 83 (25%) cases. Amplification of the other genes under investigation was observed in 4% to 6% of cases, high-grade DCIS being predominantly affected. High-grade DCIS differed significantly from low- and intermediate-grade DCIS in frequency and level of c-erbB2 amplification. In addition, high-grade DCIS revealed an accumulation of genetic aberrations. Amplification status in pure in situ lesions did not differ from intraductal carcinoma with an infiltrative component, indicating that although associated with a higher nuclear grade gene amplification might not represent an independent prognostic marker of disease progression.

The diagnosis and management of ductal carcinoma in-situ of the breast

The widespread utilization of screening mammography has produced a shift in the stage of breast cancer at diagnosis in the US: Currently, 12% to 15% of newly diagnosed breast cancer cases annually are ductal carcinoma in-situ (DCIS). The diagnosis is made, in at least 90% of patients, with mammography. Only about 10% of patients will have a palpable mass. The accurate characterization and visualization of calcifications typically requires magnification of mammographic imaging. The morphology of the calcifications is generally considered to be the most important factor in differentiating benign from malignant formations. Round and uniform shapes are more likely to be benign, while linear and heterogeneous morphologies are associated with DCIS. Following a complete mammographic work-up, most suspicious lesions are potential candidates for a stereotactic core needle biopsy. Ten percent to 50% of patients initially diagnosed with atypical ductal hyperplasia by needle biopsy have subsequently been surgically diagnosed with cancer near the biopsy site. Due to this relatively high incidence of co-existent carcinoma, a needle biopsy diagnosis of atypical ductal hyperplasia necessitates subsequent surgical excision. The most important change in our thinking about DCIS was from a monolithic view, conceiving of DCIS as a single disease highly likely to invade if left untreated, to the realization that DCIS represents a non-obligate precursor with a variable risk of progression, depending on a combination of factors, such as histology, lesion, size, and margin status. In discussing treatment options, patients should understand that local recurrence following total mastectomy is rare and that this is the procedure of choice for disease that cannot be adequately encompassed with a breast-conserving approach. If the patient and her surgeon are in agreement about proceeding with a breast-conserving approach, there needs to be a clear understanding of the incidence and implications of local recurrence. In all such discussions with newly diagnosed patients, however, it is essential to emphasize the excellent prognosis with this disease, irrespective of the surgical approach.

Analysis of cathepsin D in human breast cancer: usefulness of the processed 31 kDa active form of the enzyme as a prognostic indicator in node-negative and node-positive patients

The relative amounts of the precursor (52 kDa) and processed (31,27 kDa) forms of cathepsin D have been analyzed by Western blotting in biopsied breast tissue cytosols from 134 lesions from invasive breast cancer patients, 24 lesions from patients with ductal carcinoma in situ (DCIS), 227 lesions from benign breast disease patients, and 28 lesions from normal control subjects. The mean relative percentage amount of the 31 kDa form was significantly increased (p < 0.001) in the invasive breast cancer group compared to the other three groups. In addition, the mean relative percentage amount of the 31 kDa form was significantly increased (p < 0.05) in node-positive compared to node-negative breast cancer patients. In the benign breast disease group, patients with proliferative-type disease had a significantly increased (p = 0.02) mean relative percentage amount of the 31 kDa form of cathepsin D compared to patients with nonproliferative-type disease. Invasive breast cancer patients were followed for up to 75 months to determine if the relative percentage amount of the 31 kDa form of cathepsin D was predictive of disease-free and overall survival. Although the amount of the 31 kDa form was not predictive of disease-free survival, patients in the 'high' 31 kDa group (> 18%) were significantly (p < 0.05) more likely to die than patients in the 'low' 31 kDa group (< or = 18%). The 12 patients who died were all node-positive and in the high 31 kDa group. It thus appears that the relative amount of the processed, active 31 kDa form of cathepsin D is a useful prognostic indicator, at least in node-positive breast cancer patients.

[Histopathologic problems in the classification of pancreatic carcinoma]

The major differences between the third and fourth edition of the classification of pancreatic carcinoma are that tumors of ductal origin are divided into intraductal tumors and invasive ductal carcinoma, and atypical hyperplasia is mentioned. A low papillary or flat carcinoma in the pancreatic duct which is regarded as an early feature of ductal adenocarcinoma is classified as an intraductal tumor. However, usage of this term is not suitable from the standpoint of the outline of pathology. Minimally invasive intraductal papillary-mucinous carcinoma is classified as an intraductal tumor instead of invasive ductal carcinoma. It is often argued that minimally invasive intraductal papillary-mucinous carcinomas and invasive carcinomas derived from intraductal papillary adenocarcinoma should be distinguished. An intraductal papillary-mucinous tumor represents cystic dilatation of the pancreatic duct due to mucin secretion and papillary projection and is sometimes misdiagnosed as a mucinous cystic tumor. However, the two tumors are different. This point should be revised in the next edition. The pathologic description of the classification of pancreatic carcinoma should reflect the exact pathophysiology of these tumors and be simple.

DCIS grading schemes and clinical implications

The frequency with which ductal carcinoma in situ (DCIS) is detected has increased greatly since the introduction of mammographic screening. The number of treatment options has also increased and mastectomy has been extensively replaced by local excision with or without radiotherapy. DCIS is generally unicentric, as evidenced by the rarity with which it is bilateral and the location of recurrences at the site of previous surgery. Complete excision is thus curative but assessing adequacy of excision is beset with significant technical problems and consequently margin involvement does not correlate very well with the presence of residual disease in the breast or the development of clinical recurrence. Lesion size is related to recurrence but is also often difficult to measure. At the histological level, DCIS is a heterogeneous group of proliferations varying in cytological and architectural features, some of which are related to clinical outcome. The traditional method of classification was by growth pattern but was found to lack reproducibility and prognostic power. As a consequence, several new classifications have been proposed in recent years. Some have been assessed more rigorously than others in terms of the consistency with which they can be applied and their ability to predict clinical outcome. There is strong evidence, however, that nuclear grade is the best predictor of recurrence and the time scale over which it is likely to occur although presently it can be determined with only fair to moderate consistency. Necrosis is also a useful feature when used in combination with nuclear grade, but specifically recognizing a comedo pattern appears to have little clinical value and is associated with significant diagnostic inconsistency. No histological features to date have been found to predict the development of invasive disease. Histological assessment alone is insufficient to determine how patients with DCIS should be managed, which should also take account pathological assessment of excision margins and lesion size as well as radiological and clinical features.

A critical appraisal of existing classification systems of epithelial hyperplasia and in situ neoplasia of the breast with proposals for future methods of categorization: where are we going?

Current classification systems for borderline lesions of the breast including epithelial hyperplasia, atypical hyperplasia, and ductal carcinoma in situ fall short of the ideal. They present pathologists with problems of recognition or clear distinction and clinicians with difficult management choices. In addition, recent evidence indicates that different pathogenetic lesions are present in some categories. This article presents a brief critical appraisal of the existing classifications and offers suggestions for revision using a model of pathogenetic lineage.

Interobserver reproducibility of the Lagios nuclear grading system for ductal carcinoma in situ

Several studies have shown an association between high nuclear grade or necrosis of ductal carcinoma in situ (DCIS) lesions and the risk of local disease recurrence in patients with DCIS treated surgically with less than mastectomy. Although criteria for separating low from high nuclear grade lesions have been published, no information exists regarding interobserver reproducibility (IR). To assess IR in the classification of DCIS, six surgical pathologists from four institutions used the Lagios grading system to grade 125 DCIS lesions. Before meeting to evaluate the cases, a training set of 12 glass slides, including cases chosen to present conflicting cues for classification, was mailed to the participants with a written criteria summary. This was followed by a working session in which criteria were reviewed and agreed on. The pathologists then graded the lesions independently. The area of interest was marked on each slide before grading. After initial grading, the pathologists met again to resolve discrepant lesion classifications. A complete agreement among raters was achieved in 43 (35%) cases, with five of six raters agreeing in another 45 (36%) cases. In no case did two raters differ by more than one grade. The pairwise kappa agreement values ranged from fair to substantial (0.30 to 0.61). Generalized kappa value indicated moderate agreement (0.46, standard error = 0.02). Kappa statistics for the distinction between grades 1 and 2 and 2 and 3 were 0.29 and 0.48, respectively, (standard error = 0.02). Only one of the six raters differed significantly in scoring. With adherence to specific criteria, IR in the classification of DCIS cases can be obtained in most cases. Although these pathologists made a few grading system modifications, further refinements are needed, especially if grading will influence future therapy.

Linell classification of breast cancer morphology compared to histologic grading, S-phase fraction and DNA-ploidy

One hundred and fifty-eight histologically verified mammary carcinomas with known mammographic doubling time (DT) were studied with special emphasis on a morphologic classification proposed by Linell et al. [8, 12, 14, 15]. The hypothesis that Linell classification of ductal carcinomas into comedo, tubuloductal and tubular carcinomas is easy to perform with small inter-observer variations, was not fully confirmed. The Linell classification was found to correlate well with conventional WHO malignancy grading, S-phase fraction and DNA-ploidy. The Linell classification also correlated to surgical stage, lymph node status and DT, but not at all to tumour size. Using distant disease-free survival as an endpoint, the Linell classification gave prognostic information comparable to conventional histologic grading, seeming to be a simple, cheap and reliable method well worth trying on a larger scale.

Comparison of cytomorphological and architectural heterogeneity in mammographically-detected ductal carcinoma in situ

Many classification schemes have been proposed for ductal carcinoma in situ. Architectural heterogeneity is widely recognized. Cytonuclear grade appears to have greater prognostic significance than architectural pattern. This study assesses heterogeneity using a classification based on cytological grade and compares this to architectural heterogeneity in mammographically detected ductal carcinoma in situ. One hundred and twelve cases were classified according to architectural subtypes and the carcinoma nuclei were graded. Necrosis and microcalcification were assessed. Eighty-four percent of ductal carcinomas in situ had a single nuclear grade, whereas only 39% showed a single architectural pattern. High grade nuclei were present in 87% of cases. Necrosis was associated with high nuclear grade. In contrast to architectural heterogeneity, this study shows little ductal carcinoma in situ heterogeneity when classification is based on nuclear grade. Thus, a cytomorphological classification should have the advantage of consistency and reproducibility in comparison to architecture-based classification systems.

Immunophenotype of intraductal carcinoma

OBJECTIVE

Mammography and breast-conserving therapy have focused attention on the classification of intraductal carcinoma (IDC) and emphasized the prognostic importance of comedo versus noncomedo variants. We used histochemical markers to define the immunophenotype of 43 IDCs with respect to comedo versus noncomedo status and patterns of angiogenesis.

RESULTS

Reactions in comedo carcinomas were significantly negative for estrogen receptor and progesterone receptor, and positive for p53 and HER-2/neu more often than the noncomedo variant. All seven IDCs associated with Paget's disease showed positive reactions for HER-2/neu. Basement membrane immunoreactivity for type IV collagen and laminin was discontinuous in most examples of IDC regardless of type, with a trend toward more intense staining in comedo than in noncomedo carcinomas. Periductal angiogenesis was not significantly related to the type of IDC but was more pronounced with comedo carcinomas.

CONCLUSIONS

These observations indicate that there are immunophenotypic correlates to the current structural classification of IDC. The immunophenotype of IDC is helpful in subclassifying an IDC and could prove useful as a prognostic indicator for local control in patients treated by breast-conserving therapy.

The classification of ductal carcinoma in situ and its association with biological markers

One hundred five cases of pure ductal carcinoma in situ (DCIS) seen in the Guys Hospital breast unit between 1975 and 1991 were reviewed and reclassified using a modified histologic classification based on cytological features as well as histological architecture. The expression of p53 protein, cerbB2 protein, progesterone receptor, and a proliferation antigen KiS1, all factors reported to be of prognostic significance in invasive ductal carcinoma, was also evaluated using immunohistochemical methods. The mode of presentation of these cases was noted, and its relationship to biological markers and histologic type was also assessed. Good interobserver agreement was achieved by two independent observers using the modified histologic classification. Strong correlation was seen between histologic pattern and biological markers as well as between the individual markers. Poorly differentiated DCIS was associated with a high proliferation rate, the presence of cerbB2 and p53 protein and the absence of progesterone receptors. Well-differentiated DCIS showed the reverse, and the intermediate group showed an intermediate pattern. Paget's disease of the nipple was only seen in association with poorly differentiated DCIS, but no other significant association was noted between mode of presentation and DCIS type.

Ductal carcinoma in situ: a proposal for a new classification

Details of a proposed new classification for ductal carcinoma in situ (DCIS) are presented. This is based, primarily, on cytonuclear differentiation and, secondarily, on architectural differentiation (cellular polarisation). Three categories are defined. First is poorly differentiated DCIS composed of cells with very pleomorphic, irregularly spaced nuclei, with coarse, clumped chromatin, prominent nucleoli, and frequent mitoses. Architectural differentiation is absent or minimal. The growth pattern is solid or pseudo-cribriform and -micropapillary (without cellular polarisation). Necrosis is usually present. Calcification, when present, is amorphous. Second, at the other end of the spectrum is well-differentiated DCIS, composed of cells with monomorphic, regularly spaced nuclei containing fine chromatin, inconspicuous nucleoli, and few mitoses. The cells show pronounced polarisation with orientation of their apical border towards intercellular spaces usually resulting in cribriform, micropapillary and clinging patterns, although a solid pattern of well-differentiated DCIS also occurs. Necrosis is uncommon. Calcifications, when present, are usually psammomatous. The third category, intermediately differentiated DCIS, is composed of cells showing some pleomorphism but not so marked as in the poorly differentiated group. There is, however, always evidence of polarization around intercellular spaces, although this is not so pronounced as in the well-differentiated group. These two criteria, cytonuclear differentiation and architectural differentiation, have been found to be more consistent throughout a DCIS lesion than previously employed criteria of architectural pattern or the presence or absence of necrosis.