Basement membrane and apocrine epithelial antigens in differential diagnosis between tubular carcinoma and sclerosing adenosis of the breast

Disassembling a cancer puzzle: Cell junctions and plasma membrane as targets for anticancer therapy

Despite an enhanced permeability and retention effect typical of many solid tumors, drug penetration is not always sufficient. Possible strategies for the drug delivery improvement are a modification of the tumor cell-to-cell junctions and usage of cell membrane permeabilization proteins. In this review we discuss epithelial cell junctions as targets for a combined anticancer therapy and propose new possible sources of such agents. We suggest considering viral and bacterial pathogens disrupting epithelial layers as plentiful sources of new therapeutic agents for increasing tumor permeability for other effector agents. We also observe the application of pore forming proteins and peptides of different origin for cytoplasmic delivery of anti-cancer agents and consider the main obstacles of their use in vivo.

Differential diagnosis between sclerosing adenosis and tubular carcinoma of the breast under transmission and scanning electron microscope

The tubular carcinoma of the breast is an uncommon histological subtype of invasive breast cancer, which is generally associated with an excellent prognosis. Previous studies have demonstrated that this well differentiated variant is linked with a low incidence of lymph node involvement, a low rate of local recurrence and a high overall survival rate when compared to standard invasive ductal carcinoma. Due to its favorable prognosis, some studies have proposed that a diagnosis of tubular carcinoma might warrant less aggressive surgical or adjuvant treatment. Histologically, tubular carcinoma may mimic sclerosing adenoma or bluntduct adenosis. Its ductal nature appears well confirmed by the few ultrastructural studies of this mammary cancer. Tubular carcinoma should also be distinguished from microglandular adenosis, an uncommon form of sclerosing adenosis. The aim of this study is to prove that the ultrastructure results can give the correct diagnosis between tubular carcinoma and sclerosing adenosis.

Epitheliosis, infiltrating epitheliosis, and radial scar

The lesion termed "infiltrating epitheliosis" (IE) by Azzopardi is described using his original criteria. The differential diagnosis from radial scar (RS) is discussed. It appears that IE and RS are histologically and histogenetically different and are also associated with a different risk of carcinoma. IE can be associated with either in situ or invasive carcinoma, whereas RS being more like a process of involution is very seldom involved by a carcinoma. Therefore, whatever name is used among the several found in the literature, it should be made clear they are not interchangeable when reporting on lesions like IE and RS.

Loss of types XV and XIX collagen precedes basement membrane invasion in ductal carcinoma of the female breast

Ductal and lobular carcinomas comprise most malignancies of the female breast and the morbidity and mortality associated with breast cancer. During the progression from in situ to invasive stages, tumour cells penetrate the epithelial and vascular basement membranes (BM) to realize full metastatic potential. While the definition of these structures has primarily resulted from analysis of laminin and type IV collagen, characterization of newly discovered BM/BM zone (BMZ) proteins will further elucidate the interactions between tumour cells and the host stroma. We have studied the expression of two non-fibrillar BMZ collagens, the type XV proteoglycan and collagen XIX, in breast cancer where a linear, well-formed BM becomes fragmented and even lost in the progression of epithelial malignancy. In the normal breast, types XV and XIX were found in all BMZ: epithelial, muscle, neural, endothelial, and fat. In in situ lesions, these two collagens, and particularly type XV, were often absent from the BM/BMZ displaying a continuous or just focally disrupted type IV/laminin staining pattern. In contrast, infiltrating ductal carcinomas showed only rare traces of laminin and collagen IV reactivity adjacent to the glands and tumour nests, and similarly there was little if any evidence of types XV and XIX collagen. All four molecules were, however, detected in the interstitium associated with some of the invasive carcinomas. The data suggest that types XV and XIX collagen are lost early in the development of invasive tumours, prior to penetration and eventual dissolution of the epithelial BM. Disappearance of these proteins from the BM/BMZ may signal remodelling of the extracellular matrix to promote tumour cell infiltration.

Immunocytochemical study of type IV collagen and laminin in canine mammary tumours

We performed an immunohistochemical study of the basement membrane (BM) proteins laminin and type IV collagen in 35 canine mammary tumours, histologically classified according to the World Health Organization's suggested classification. Laminin and type IV collagen were seen in extracellular locations but only laminin was present in epithelial and myoepithelial cells and chondrocytes. The BM was always continuous in adenomas and fibroadenomas. In the 20 malignant tumours studied, the basement membrane was continuous in one, discontinuous in five, and virtually absent in 14. When present, the BM of malignant tumours varied in width and distribution in the same area. The benign and malignant mixed tumours did not have BM separating epithelial and newly-formed mesenchymal structures. In areas of abundant myoepithelial cells in complex and mixed tumours, both benign and malignant, there were groups of BM fragments which differed in length and thickness and occasionally formed tangles. We have called these 'membranous thickets'. Our results indicate that myoepithelial cells are the main source of the BM proteins laminin and type IV collagen in canine mammary tumours.

Distribution of laminin, type IV collagen and fibronectin in the invasive component of breast carcinoma

Laminin, type IV collagen and fibronectin were examined immunohistochemically in the invasive component of breast carcinomas. Laminin was expressed around the invasive carcinoma cell nests in 38 (54%) of 71 cases. Immunoreactivity for type IV collagen was observed around the invasive carcinoma cell nests or the stroma apart from carcinoma cells in 44 (80%) of 55 cases. Fibronectin was strongly expressed in the stroma only in 75 (99%) of 76 cases. The expression of laminin significantly correlated with tubular formation in the invasive carcinoma cell nests and showed a tendency to be correlative to estrogen receptor (ER) and progesterone receptor (PgR) of carcinoma tissue, but no correlation among laminin expression, histological type, the age of patients, tumor size and lymph node metastasis was noted. Type IV collagen and fibronectin did not correlate to any clinicopathological factors such as histological type, grade of differentiation, the age of patients, tumor size, lymph node metastasis, ER and PgR status. No concordant expression of these extracellular matrices was seen.

Myoepithelial and basement membrane antigens in benign and malignant human breast tumors

Serial cryostat sections of 160 human breast lesions and of 9 lymph-node metastases were studied by indirect immunofluorescence. We used monoclonal antibodies (MAbs) to lining-epithelium-specific keratin 8 and to myoepithelium-specific keratin 17 in combination with polyclonal and monoclonal antibodies to major basement membrane components, laminin, collagen type IV, entactin/nidogen, and large heparan sulfate proteoglycan (perlecan) core protein. Continuous basement membranes adjacent to a basal layer of keratin-17-positive myoepithelial cells were typical for normal, benign and in situ carcinomatous structures. In invasive and metastatic structures, always formed by keratin-8-positive tumor cells, basement membranes were found only rarely and with conspicuous fragmentations. This lack of basement membranes correlated with loss of myoepithelium identified by staining for keratin 17. In comedo structures of invasive ductal carcinomas and in papillary carcinomas, fibrovascular complexes with numerous blood vessels and deposition of basement membrane material were often seen in the stroma. Immunomorphological analysis of 41 cases of doubtful diagnosis at intra-operative biopsy was also performed. A combination of MAbs to keratins 8 and 17, and to basement membrane components, made it possible to distinguish between morphologically similar benign and malignant proliferations and to detect single-cell invasion of the stroma. This combination of antibodies may be recommended as an auxiliary immunomorphological tool for differential diagnosis of intra-operative breast biopsies in dubious cases.

Assessment of invasion in breast lesions using antibodies to basement membrane components and myoepithelial cells

This paper describes immunostaining of consecutive sections from 15 cases of fibrocystic change of the breast (including 2 examples of intraductal papilloma), 4 ductal carcinomas-in-situ and 17 invasive carcinomas (4 tubular, 1 papillary, 2 lobular and 10 infiltrating ductal, NOS) with antisera to components of the basement membrane (BM), type IV collagen and laminin, and with the muscle antibodies actin and muscle-specific actin. A simple digestion technique was developed to improve the clarity of BM staining with these antibodies. The BM stains facilitated identification of small invasive foci through breaks in the BM in 2 of the cases which had been reported as pure intraductal carcinoma. Tubular carcinomas were surrounded by abnormal, fragmented, and focally discontinuous BM, a feature which could be used to distinguish this well-differentiated breast carcinoma sub-type from sclerosing adenosis, in which individual acini were invariably surrounded by a continuous BM. BM staining emphasized the fibrovascular core of intraductal papillomas, whereas the BM layer was absent in intraductal, cytologically malignant, papillary projections. Similarly, myoepithelial cells, stained with antisera to muscle actins, were identified in a continuous layer surrounding benign epithelial proliferations. These immunohistochemical staining techniques may thus assist the diagnostic histopathologist in differentiating between benign epithelial proliferations of the breast and well-differentiated invasive breast carcinoma, and in identifying foci of microinvasive carcinoma.

Monoclonal antibodies for radioimmunoscintigraphy of breast cancer

Breast cancer is the leading cause of cancer deaths among females, and it is estimated that each year, one in ten American women will be newly diagnosed as having the disease. It is therefore not surprising, that a great deal of effort has been made to better understand the biology of breast cancer, and that investigators keep up the search for new tools to better characterize, diagnose and treat these tumours. In this regard, the introduction of the hybridoma technique in 1975 by Kohler and Milstein has lead to an extensive work in the characterization of monoclonal and polyclonal antibodies against breast cancers. A large number of antibodies has been raised to different epitopes present in normal and neoplastic breast tissue; but unfortunately we have yet to find a highly sensitive and specific monoclonal antibody for breast cancer that can successfully be used for scintigraphic detection of nodal metastases and for radioimmunotherapy treatment of this disease. As possible radioimmunodiagnostics, antibodies are known which react with the following antigens: (1) cytoskeletal proteins (2) breast cell products (3) steroid receptors (4) putative tumor-associated antigens (5) oncogene products (6) pregnancy-related products (7) basement membrane antigens (8) degradative enzymes (9) cell receptors for extracellular matrix molecules (10) multidrug resistance gene product (p-glycoprotein) (11) proliferative markers.

Expression of laminin in benign and malignant sclerosing lesions of extrahepatic bile ducts

The distribution of laminin, a basement membrane glycoprotein, was studied by an immunohistochemical technique in six samples of benign sclerosing lesions of extrahepatic bile ducts and in 11 sclerosing cholangiocarcinomas. The expression of laminin showed that benign glandular structures were surrounded by a mainly intact basement membrane. In sclerosing cholangiocarcinomas laminin was irregularly distributed, and in large areas totally absent. The findings suggest that deposition of basement membrane material is defective. Sclerosing cholangitis may be extremely difficult to distinguish from well differentiated sclerosing cholangiocarcinoma. This sample was small, but the diseases studied were relatively rare. Staining for laminin might be of additional use to surgical pathologists in the differential diagnosis of benign sclerosing lesions and sclerosing cholangiocarcinomas.

Detection of basement membrane components and basal cell keratin 14 in noninvasive and invasive carcinomas of the breast

Using immunohistochemistry, the distribution patterns of basement membrane components type VII collagen (monoclonal antibody LH7.2), type IV collagen, and laminin were investigated in normal and malignant human breast tissue and compared with that of keratin 14 (monoclonal antibody LL002), which is expressed only by the basal (myoepithelial) cells in the secretory epithelia of the mammary gland. In normal breast tissue as well as in intraductal carcinomas, a more or less continuous basement membrane was observed at the epithelial stromal interface. Unlike laminin and type IV collagen, type VII collagen was not detected in the basement membrane of blood vessels. The keratin 14 antibody stained the basal cell layer of normal ducts and ducts with in situ cancer. In 85% of the invasive carcinomas no basement membrane or basal cells were detected. In 13 cases, however, laminin, type IV collagen, and/or type VII collagen were detected around tumor nests and individual tumor cells. Five of these tumors also showed a positive reaction with the keratin 14 antibody. In five cases keratin 14 expression was found without detectable basement membrane components. It is concluded that 18 of 103 invasive ductal breast carcinomas examined in this study exhibit a basal cell phenotype as determined from the expression of keratin and the deposition of basement membrane components.

Paucity of fibronectin in invasive lobular carcinoma of breast

Fifty-four cases of invasive carcinoma of breast were immunostained for fibronectin and laminin. They included 36 cases of invasive ductal carcinoma and 18 cases of invasive lobular carcinoma. Although there was some heterogeneity within tumours, it was found that whilst the majority of ductal carcinomas (31/36) had abundant fibronectin at cell/stroma boundaries or diffusely throughout stroma, a substantial proportion of lobular carcinomas (12/18) had very little (P less than 0.001). This difference could not be related to differences in laminin immunoreactivity, which was most commonly scanty or absent in both tumour types. It is postulated that the characteristic infiltration pattern of lobular carcinoma may be attributed in part to paucity of stromal fibronectin.

Monoclonal antibody mapping of keratins 8 and 17 and of vimentin in normal human mammary gland, benign tumors, dysplasias and breast cancer

The distribution of keratins 8 and 17 and of vimentin in 28 normal human mammary tissue samples, 16 benign tumors, 26 fibrocytic diseases and 52 malignant breast tumors have been studied using monoclonal antibodies HI, E3 and NT30, respectively. Three cell populations in normal mammary epithelium have been identified: luminal epithelium containing keratin 8, myoepithelium of the lobular structures positive for vimentin, and myoepithelium of extralobular ducts positive for keratin 17. In different kinds of benign tumor and dysplastic proliferation a mosaic of cells with all normal phenotypes has been observed. The majority of cells co-expressed keratins 8 and 17 or vimentin. In the overwhelming majority of carcinomas, cells did not contain myoepithelial markers (keratin 17 and vimentin) but expressed only keratin 8 specific to normal luminal epithelium.

Immunohistochemical localization of myoepithelial cells and basement membrane in normal, benign and malignant human breast lesions

Distributions of actin and type IV collagen were investigated immunohistochemically as markers for myoepithelial cells and basement membranes. Carnoy's and Methacarn-fixed, paraffin-embedded tissues from 103 human breast lesions from 103 patients were examined; 65 with carcinomas, 27 with mastopathies, 9 with fibroadenomas and 2 with phyllodes tumours. Fifty-five samples of the normal mammary gland tissue adjacent to tumours were also included for comparison. In normal breast and benign breast diseases, type IV collagen was identified around the mammary glandular cells and actin-positive cells were demonstrated to attach to basement membranes. In noninvasive carcinomas, type IV collagen was found as a continuous lining around a cell nest, while actin-positive cells were usually absent in ductal but quite numerous in lobular carcinomas. In invasive carcinomas, type IV collagen was fragmented or absent and actin-positive cells were very uncommon around the fragmentary basement membranes. These results suggest that the different distributions of myoepithelial cells and basement membrane material is useful in the differential diagnosis of surgical pathology of the breast.

Patterns of basement membrane deposition in benign and malignant breast tumours

We have examined epithelial basement membranes in tissue samples of seven normal breasts, 64 benign breast lesions and 63 malignant breast tumours by immunocytochemistry, using polyclonal antisera specific for type IV collagen. In normal breast tissue as well as in all benign tumours a continuous basement membrane was found at the epithelial stromal interface. In benign proliferative lesions, epitheliosis and papillomatosis could be more accurately distinguished with basement membrane staining. This approach also facilitated the differentiation between sclerosing adenosis and tubular carcinoma, since the tubules in sclerosing adenosis are surrounded by a continuous basement membrane whereas in tubular carcinoma basement membranes are almost entirely absent. In radial scar lesions the tubules were always surrounded by intact basement membranes, which underlines the fact that these are benign lesions. In breast carcinoma we could not detect a relationship between histological grade and the extent of basement membrane deposition. However, in different tumour types the basement membrane alterations varied. In infiltrating lobular carcinoma of the alveolar type, fragments of basement membrane were found, whereas in the classic and trabecular type, basement membranes were absent, suggesting that the alveolar type may be an intermediate phase in the progression of lobular carcinoma in situ to infiltrating lobular carcinoma. It is concluded that basement membrane immunocytochemistry, using antibodies to type IV collagen, is useful in the differentiation between benign and malignant breast lesions and in the classification of breast neoplasms.

Occurrence of basement membranes in pigment cell tumors of the skin, relation to cell type and clinical behavior

The occurrence, location and intensity of the basement membrane (BM) components collagen IV and laminin in benign and malignant pigment cell tumors was studied by immunohistochemical methods. The results seemed to establish the following findings: junctional nevi display varying continuity of BM; nevus cells in the dermis display more continuous and thicker BM superficially (associated with epithelial type nevus cells); superficial spreading melanoma displays discontinuity of BM, and nodular melanoma and metastatic melanoma display variable BM around tumor aggregates. The variable expression of BM components in this study showed an apparent relationship to tumor cell type and laminin and collagen IV production, partly related to clinical behaviour.

Immunohistochemical detection of laminin in 98 human breast carcinomas: a light and electron microscopic study

The distribution of laminin was studied in 98 breast carcinomas with antilaminin and the avidin-biotin-peroxidase complex method. Laminin was observed within vascular and epithelial basement membranes. Laminin displayed a continuous linear pattern in intraductal carcinomas, and it was heterogeneously distributed, with a discontinuous linear pattern, in invasive carcinomas. No intracellular laminin staining was detected. Electron microscopic study showed laminin immunostaining in the lamina densa of basement membranes in nonneoplastic breast tissue. In tumors, laminin immunostaining frequently revealed multilayered basement membranes and abnormal multilayered basement membranes in blood vessels in the tumor stroma. These data suggest that laminin immunostaining, as a new approach to the heterogeneous basement membrane changes occurring in carcinomas, should permit better understanding of cell diffusion processes and of stroma-tumor cell interactions. The consistent extracellular distribution of laminin in contact with the stroma indicates that the latter plays an important role in the assembly of basement membrane components.

Adenoid cystic carcinoma of the breast: a case with axillary lymph node metastasis

A breast tumour with proven lymph node metastasis is conclusively characterized as an adenoid cystic carcinoma using immunocytochemistry and electron microscopy. The majority of tumour cells showed certain of the characteristic features of myoepithelial cells while the pseudocystic spaces contained large amounts of reduplicated basal lamina. A small proportion of tumour cells, however, showed epithelial differentiation with the formation of true lumina.

Semiautomated measurement of rapidly hydrolyzed DNA in the diagnosis of mammary carcinoma

A modified Feulgen procedure combined with integrating microdensitometry was used to quantify the rapidly hydrolyzed DNA fractions in nuclei obtained from primary carcinomas of the human breast. The method, which was semiautomated by interfacing the microdensitometer with a Research Machines 380Z microcomputer (Research Machines, Ltd., Oxford, UK), could distinguish malignant carcinomas from benign breast lesions. It is proposed that the semiautomated assessment of rapidly hydrolyzed DNA fractions could serve as a reliable additional parameter on which to diagnose breast malignancies.

Follicular thyroid tumours: a study of laminin and type IV collagen in basement membrane and endothelium

Immunocytochemical stains for laminin and type IV collagen can be used as markers for basement membrane and vascular endothelium. Thirty four follicular thyroid lesions were examined using these techniques to investigate two aspects: firstly, the relation between the extent of invasion and the integrity of basement membrane; secondly, whether the techniques could enhance the detection of tumour vascular invasion. The results showed that although basement membrane was lost in widely invasive tumours, preservation was seen in most but not all encapsulated tumours. The potential for improved recognition of vascular invasion was also found.

The pattern of distribution of laminin in neurogenic tumors, granular cell tumors, and nevi of the oral mucosa

Oral tumors of presumably neuroectodermal origin were stained with anti-laminin antibody by a double layered immunofluorescence technique. A marked positive staining for laminin was found in neurofibromas and neurilemmomas although the pattern of laminin distribution was slightly different. Accentuated staining was seen in Verocay bodies. In granular cell myoblastomas (GCM), small groups of tumor cells were encircled by laminin-positive material, whereas individual tumor cells were unstained. In nevi, diffusely spread nevus cells were surrounded by a rim of laminin, whereas when arranged in nests whole groups of cells were encircled by laminin as seen in the GCM. Ordinary oral fibromas included as controls were negative except for the expected positive staining of basement membranes normally occurring in the tissues. Immunohistochemical demonstration of laminin seems to be a valuable aid in differential diagnosis of soft tissue tumors and may provide useful information about the pathogenesis of various lesions.

Antiserum against formalin-fixed human milk fat globule glycoprotein for immunohistochemistry of normal and malignant apocrine epithelium

A rabbit antiserum was raised against formalin-fixed glycoprotein isolated by lectin affinity chromatography from human milk fat globules. After adsorption with erythrocytes and normal blood leukocytes the antiserum detected in immunoblotting of fresh mammary carcinoma tissue a major component of 75 000 dalton apparent molecular weight. The antiserum specifically decorated normal and malignant apocrine epithelium in sections of formalin-fixed tissues. The usefulness of such antisera for routine immunohistochemical diagnosis of metastatic carcinomas is demonstrated.

Expression of laminin in thyroid gland and thyroid tumors: an immunohistologic study

Thirty-five thyroid tumors and four normal thyroids were immunohistochemically investigated for the presence of laminin, a major basement membrane component. The thyroid follicles in normal tissues and in nodular goiters were surrounded by a continuous rim of laminin positivity, as were also the papillae of papillary carcinomas. Follicular adenomas and well-differentiated follicular carcinomas also showed laminin positivity around most of the follicles. Anaplastic thyroid carcinoma lacking a distinct compartmentalization of tumor cells also lacked pericellular laminin. However, in contrast to all other thyroid tumors, an intense laminin positivity was found in scattered tumor cells of anaplastic carcinomas. Laminin positivity is thus a feature reflecting the differentiation level of thyroid tumors, but, unlike most other carcinomas, differentiated thyroid tumors have basal laminae surrounding the differentiated structural units.