Discontinuity of the basement membrane in fibrosing basocellular carcinomas and basosquamous carcinomas of the skin: an immunohistochemical study with human laminin and type IV collagen antibodies

Cutaneous Superficial Basal Cell Carcinoma is a Basal Cell Carcinoma In Situ: Electron Microscopy of a Case Series of Basal Cell Carcinomas

Basal cell carcinoma (BCC) is the most common skin cancer. Skin cancers may present either as a non-invasive tumor or an invasive malignancy. The terminology of carcinoma in situ is used when the tumor is either just limited to epidermis or not present as single cells or nests in the dermis. However, currently the terminology superficial BCC is inappropriately used instead of BCC in situ when the skin cancer is limited to epidermis. In this study we compare the pathologic changes of superficial, nodular, and infiltrative BCCs using electron microscopy to identify the ultrastructural characteristics and validate the previously proposed terminology. Three cases of BCC (superficial BCC, nodular BCC, and infiltrative BCC) diagnosed by dermatopathologists at our institute were selected for review. Paraffin block tissues from these cases were sent for electron microscopy studies which demonstrated disruption of basal lamina in both nodular and infiltrative type of BCC, while it remains intact in BCC superficial type after extensive examination. Therefore, similar to other in situ skin cancers, there is no invasion of the neoplasm in superficial BCC into the dermis. Hence, the older term superficial BCC should be appropriately replaced with the newer terminology BCC in situ.

Physical defects in basement membrane-mimicking collagen-IV matrices trigger cellular EMT and invasion

In fibrosis and cancer, degradation of basement membrane (BM) and cell invasion are considered as key outcomes of a cellular transformation called epithelial-mesenchymal transition (EMT). Here, we pose a converse question - can preexisting physical defects in the BM matrix cause EMT in normal epithelial cells? On a BM-mimicking matrix of collagen-IV-coated polyacrylamide (PA) gel, we have discovered a reverse phenomenon in which preexisting defects trigger EMT in normal epithelial cells. Through spatiotemporal measurements and simulations in silico, we demonstrate that the EMT precedes cellular mechanoactivation on defective matrices, but they occur concurrently on stiff matrices. The defect-dependent EMT caused cell invasion though a stroma-mimicking collagen-I layer, which could be disabled through MMP9 inhibition. Our findings reveal that the known BM degradation caused by cellular EMT and invasion is not a one-way process. Instead, normal epithelial cells can exploit physical defects in the BM matrix to undergo disease-like cellular transformations.

TGFβ, Fibronectin and Integrin α5β1 Promote Invasion in Basal Cell Carcinoma

Basal cell carcinoma (BCC) is the most frequent human cancer and is becoming an important health problem in an aging population. Based on their clinical and histological characteristics, thick BCC are typically divided into low-risk nodular and high-risk infiltrative subtypes, although the underlying mechanisms are poorly understood. We have identified molecular mechanisms that explain the aggressiveness of high-risk infiltrative BCC, with a potential direct clinical impact. In this study, we first show that fibroblasts, transforming growth factor-β, and fibronectin are found preferentially in infiltrative human BCC. This allowed us to develop in vivo models for the study of infiltrative BCC, which in turn let us confirm the role of transforming growth factor-β in inducing peritumoral fibronectin deposition and tumor infiltration. We then show that fibronectin promotes adhesion and migration of BCC cell lines through integrin α5β1-mediated phosphorylation of focal adhesion kinase. Fittingly, both inhibition of integrin α5β1 and phospho-focal adhesion kinase prevent fibronectin-induced migration of BCC cells in vitro as well as BCC infiltration in vivo. Altogether, our results open important insights into the pathogenesis of aggressive infiltrative BCC and identify integrin α5β1 or focal adhesion kinase inhibition as promising strategies for the treatment of advanced BCC.

[Desmoplastic trichoepithelioma: a clinicopathological study, including a comparison with morpheiform basal cell carcinoma]

BACKGROUND

Desmoplastic trichoepithelioma (DTE) is an uncommon form of adnexal tumour that was described for the first time as a separate clinicopathological entity in 1976. We carried out a retrospective histopathological study of a large series of cases of DTE in order to better characterise this tumour and compare it with sclerodermiform basal cell carcinoma (BCC), which is in fact the most common as well as the most complex type of differential diagnosis.

PATIENTS AND METHODS

We included in this study all cases of DTE diagnosed between 1979 and 2001 at our dermatopathology laboratory. The clinical features were taken from the patient files. Diagnosis was confirmed by two different examiners and all microscopic elements were reviewed. The same clinical and demographic data were collected for cases of BCC diagnosed over the same period.

RESULTS

We included 68 cases of DTE in 67 patients in our study, of whom 83.5% were women, and the mean age was 42.8 years. Lesions were found primarily on the head (98.5% of cases), mainly on the cheeks (29.2% of cases) and forehead (23.1% of cases). The diagnosis was only made by the clinician in four cases; in 38 cases the diagnosis made was BCC. In all cases, histological examination revealed thin lines of basaloid epithelial cells associated with small keratinising cysts. A common finding was granulomas with foreign bodies and calcifications. In six cases (8.8%), a tumour combining DTE with an intradermal naevus was observed. Mean clinical follow-up of 8 years (1 to 23 years) in 29 patients showed absence of relapse or metastasis. Over the same period, 662 cases of BCC were recorded in 499 patients, 58.9% of whom were women. The mean age was 65.6 years. The principal location was the nose (34% of cases). No cases of associated naevus were recorded.

COMMENTS

DTE is a firm plaque-like lesion, flesh coloured or yellowish, and generally with a depressed centre; it is seen primarily in middle-aged women and occurs principally on the cheeks and forehead. There is a significant association with naevus, a singular feature among adnexal tumours. On average, it is 10 times less common than BCC. The size of our study groups shows for the first time distinguishing features with regard to BCC, for which the age of onset is far higher and predominance among women less marked. Further, the sites are different, with BCC being seen predominantly on the nose while DTE is seen mainly on the cheeks. A suggested clinical diagnosis is thus possible.

Are encapsulated papillary carcinomas of the breast in situ or invasive? A basement membrane study of 27 cases

Encapsulated papillary carcinoma (EPC) of the breast is traditionally considered a variant of ductal carcinoma in situ (DCIS). However, recent studies show EPCs lack myoepithelial cells at their periphery, leading some to conclude that EPCs are invasive. We used a robust collagen type IV immunohistochemical procedure to assess invasion in 21 cases of pure EPC and 6 EPCs with adjacent invasive ductal carcinoma (IDC) and compared these results with those for papilloma, DCIS, and IDC. Moderate to intense collagen type IV expression was seen in all EPCs and was absent or decreased in all IDCs. All patients with pure EPC had negative axillary nodes with the exception of 1 who had a micrometastasis, and all were alive with no evidence of disease at follow-up (mean, 40.4 months). EPCs are in situ carcinomas with an excellent prognosis and can be managed with local therapy with or without sentinel lymph node biopsy.

Basosquamous carcinoma

BACKGROUND

Basosquamous carcinoma is considered an aggressive type of basal cell carcinoma (BCC) with an increased risk of recurrence and metastases. This concept has been perpetuated in the literature in spite of confusing terminology, limited scientific data, and the contradictory surgical experiences of some observers.

METHODS

This is a narrative review based on a MEDLINE search of articles in English and a manual search of popular dermatology textbooks to define basosquamous carcinoma, its incidence, clinical behavior, and treatment of choice.

RESULTS

There are no specific clinical features to distinguish basosquamous carcinoma from other BCC types and the diagnosis is made only after biopsy. There are several histologic definitions of basosquamous carcinoma ranging from a characteristic combination of BCC and squamous cell carcinoma with or without a transition zone, to any BCC with evidence of keratinization. The authors confine the use of the term to an infiltrative growth BCC with areas of keratinization and/or intercellular bridge formation in the setting of a prototypic proliferative stromal reaction. The term "metatypical basal cell carcinoma" is considered a synonym but its use is discouraged for the reasons outlined. The reported incidence of basosquamous carcinoma ranges from 1.2% to 2.7%. Published recurrence rates are 12% to 51% for surgical excision and 4% for Mohs micrographic surgery. The incidence of metastasis is at least 5%. The aggressive biological behavior and clinical course distinguish basosquamous carcinoma from other forms of BCC.

LIMITATIONS

This study is a literature review, contains a limited number of patients, and is mostly retrospective studies.

CONCLUSION

The terminology surrounding basosquamous carcinoma is confusing and there is a need for more uniform language. Based on our review and personal experience, we propose a more precise and specific definition. Data regarding the incidence, recurrence, and metastasis rates of basosquamous carcinoma are based mostly on retrospective series with a limited number of cases. We conclude that although the incidence of basosquamous carcinoma is unknown, there is a literature precedent suggesting more aggressive biological behavior. We believe that complete surgical excision is the preferred approach, and that basosquamous carcinoma is an ideal candidate lesion for Mohs micrographic surgery.

Spectrophotometric intracutaneous analysis in the diagnosis of basal cell carcinoma: a pilot study

BACKGROUND

The SIAscope is a portable imaging device that uses a hand-held unit to emit light of varying wavelengths when placed on the skin. The components of skin absorb light to known extents and any reflected light is received by the hand-held unit. This information is processed by the SIAscope software to produce images on a computer screen, displaying the melanin, blood, and collagen in the area of concern. Hypothesis/aims Previous research has shown the SIAscope to be both highly sensitive and specific for melanoma diagnosis. The SIAscope has not, however, been previously investigated for nonmelanoma skin cancer diagnosis. We therefore conducted a pilot study to investigate such potential.

METHODS

Having gained ethical approval, 20 consecutive lesions were scanned using the SIAscope, and the images were examined for features that may be indicative of nonmelanoma skin cancer.

RESULTS

The findings of branched vessels and vascular "flare" were indicative of a lesion being a basal cell carcinoma. Focal paleness and collagen changes were less specific in this study, but may prove to be valuable features in further studies.

CONCLUSIONS

This pilot study implies that the SIAscope may indeed provide an accurate method for basal cell carcinoma diagnosis by identifying features specific for such lesions. Further studies to investigate nonmelanoma skin cancer diagnosis, and to explore any potential to differentiate between basal cell carcinomas and squamous cell carcinomas and between superficial and thicker basal cell carcinomas by the SIAscope, are warranted.

Basal cell carcinoma: biology, morphology and clinical implications

Basal cell carcinoma (BCC) is the most common malignant neoplasm of humans. Rising dramatically in incidence in North America, as likely reflects changing habits of the population and a move from more northerly climes to the sunbelt of the Southern and Southwestern United States, the incidence is surely to rise even higher in the future. The last decade has seen significant advances in our understanding of BCC biology and novel approaches to therapy, which hinge upon accurate diagnosis and subclassification by pathologists. The purpose of this review article is to summate the research advances in our understanding of BCC biology and to acquaint pathologists and clinicians to the practical issues in BCC diagnosis and subclassification which flow there from.

Evaluation of basement membrane status in aggressive skin carcinomas with skull base invasion: a case-control study

Some skin carcinomas may be very aggressive. Breached of basement membrane (BM) has been in some situations associated with tumor aggressiveness. In this study, the status of BM in invasion was evaluated in basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs) with skull base invasion, and it was compared with tumor's good outcome. Integrity or breached of BM was visualized using immunohistochemistry technique with anti-type IV collagen antibody. The pattern of BM was classified as intact, breached, or absent in 24 BCCs and 11 SCCs with skull base invasion. Control group (good outcome) included 23 BCCs and 10 SCCs. Breached BM and absence of BM were respectively noted in 33.33% and 45.83% of BCCs with skull base invasion, compared with 8.33% and 17.395% in the control group ( P < .001). Regarding SCCs, ruptured and absent BMs were, respectively, noted in 36.36% and 63.64% of BCCs with skull base invasion, compared with 30% and 30% in the control group ( P = .075). In this study, destruction of BM was significantly more common in BCCs with skull base invasion, in comparison with those with good outcome. In SCC, this difference was not statistically significant.

Differential expression of alpha1 (IV) and alpha5 (IV) collagen chains in basal-cell carcinoma

BACKGROUND

Basement membrane alterations are common in malignancies, and they may indicate tumoral aggressiveness. Distinct patterns of tumoral coverage by collagen IV were reported in nodular and aggressive basal-cell carcinomas (BCCs). Differential expressions of alpha (IV) collagen chains were also shown on frozen sections. The aim of our work was to document the immunohistochemical expression of alpha1, alpha3, and alpha5 (IV) collagen chains in BCC after routine fixation and processing.

METHODS

The patterns of distribution of alpha1 (IV), alpha3 (IV), and alpha5 (IV) collagen chains were studied in 20 formalin-fixed and paraffin-embedded BCCs showing different infiltrative patterns. One trichoblastoma was used as control.

RESULTS

In nodular BCCs, the expression of alpha5 (IV) collagen chain was downregulated and uneven. By contrast, alpha1 (IV) collagen chain expression was preserved around these tumors similar to the surrounding skin. However, the alpha1 (IV) collagen chain expression was discontinuous or absent in BCC areas showing an infiltrative pattern of extension. The alpha3 chain was absent both underneath all BCCs and non-neoplastic skin.

CONCLUSIONS

The basement membrane alterations around nodular BCCs involved more precisely the alpha5 (IV) collagen chains. Defects in alpha1 (IV) collagen chain expression seemed to be associated with a tumoral invasive and infiltrative pattern. The biological significance of these findings is unclear.

CD44 is exposed to the extracellular matrix at invasive sites in basal cell carcinomas

We have previously shown, by light microscopy, that the level of expression of CD44 (pan-CD44, CD44v3, CD44v5, and CD44v6) in human basal cell carcinomas is related to growth pattern and invasiveness (Br J Dermatol 1099;140:17-25). We have now studied the fine distribution of these CD44 isoforms in the same tumors using immunoelectron microscopy. Despite the strong differences in the level of expression in tumor areas with different growth patterns, CD44 was consistently found almost exclusively at intercellular surfaces, with a very strong predilection for widened intercellular pouches, ie, identical to the distribution in the normal epidermis. This prevalent distribution corroborates a role for CD44 in maintaining hyaluronan-filled spaces (J Histochem Cytochem 1998;46:241-248). However, the correlation between the presence of CD44 and the presence of such pouches was not absolute, indicating that other factors are involved as well. In contrast to the prevailing literature, we also found a weak but distinct labeling of cell surfaces facing the extracellular matrix. Interestingly, this appeared significantly elevated in the thinnest, most irregular, and usually most peripheral tumor cell strands, where it was associated with tumor cell protrusions and absence of a basal lamina. Thus, the CD44(+) protrusions were in direct contact with the extracellular matrix and apparently represented sites of invasion. The mechanisms that may contribute to a role of CD44 at these sites include binding of extracellular matrix components (notably hyaluronan) and several biologically active factors such as hepatocyte growth factor/scatter factor and matrix metalloproteinase 9.

Prognostic value of apoptotic index in cutaneous basal cell carcinomas of head and neck

Basal cell carcinoma (BCC) is the most common type of human cancer, often locally invasive, and following a benign clinical course. However, a proportion of BCCs do recur after treatment, causing extensive local tissue destruction, seldom metastasizing. Morphological methods to unequivocally distinguish the aggressive forms of these tumors (BCC2) from the ordinary ones (BCC1) have so far been lacking. Apoptosis, or programmed cell death, is thought to be important for the death of tumor cells in various stages of carcinogenesis. We analyzed the extent of apoptosis in BCCs of head and neck in a morphological, morphometric, and electron-microscopic study, to estabilish on a retrospective basis, the relative frequency of recurrence of tumors showing different apoptotic rates. We found that BCC1 showed lower apoptotic index (AI) than BCC2 [BCC1: AI from 2.03 to 10.45% (mean value: 5.98%) BCC2: AI from 21. 91 up to 43.82% (mean value: 39.82%)]. The morphometric analysis of both BCC1 and BCC2 revealed significant differences between the values concerning nuclear area, length, perimeter, and roundness of the apoptotic cells with respect to the 'viable' neoplastic cells. Electron-microscopy confirmed that the features of morphological apoptotic cells were characteristic of programmed cell death. We hypothesized that low apoptotic rates in BCC1 could be indicative of a good prognosis. In fact, this corresponded to an 'expansive' but not still invasive neoplastic state. In this phase, however, the tumor cells may constitute the target for genetic changes triggered by enviromental physical or chemical mutagenic agents, such as UV rays. BCC2, then, could be the result of newly selected mutated neoplastic cellular clones, with more aggressive biological behavior. The high apoptotic level found in BCC2 could thus be used as an indirect alarm signal from pathologists. This hypothesis seems to be supported by most of the current data in the literature and by the clinical outcome of BCC2 of our series. In our opinion, routine evaluation of apoptosis in BCCs could be proposed to facilitate their sub-classification, contributing toward the evaluation of the prospective outcome of the individual patients.

Expression of the laminin gamma2 chain in different histological types of lung carcinoma. A study by immunohistochemistry and in situ hybridization

Sixty-four malignant lung tumours and 12 of their regional lymph node metastases were analysed for expression of the laminin gamma2 chain by immunohistochemistry and in situ hybridization. Expression of the laminin gamma2 chain was strongest in squamous cell carcinomas, followed by adenocarcinomas and large cell carcinomas. Positive cells, except for large cell carcinomas, were located at the epithelial-stromal interface of tumour clusters. An important exception was small cell lung carcinoma, with only a low level of laminin gamma2 chain expression. Apart from tumour type, this may reflect the relatively scanty fibrous stroma in these tumours and supports previous observations that small cell lung carcinoma cells, contrary to other types, lack surface expression of alpha(6)beta(4) integrin, the specific laminin-5 binding receptor. In frozen sections, immunohistochemistry showed linear basement membranes around tumour clusters in squamous cell carcinomas and adenocarcinomas. This shows that carcinoma cells are capable of heavy deposition of the laminin gamma2 chain around tumour clusters and suggests that a laminin gamma2 chain-containing substrate may be of significance for the spread and growth of malignant tumours.

Abnormal expression of epiligrin and alpha 6 beta 4 integrin in basal cell carcinoma

BACKGROUND

Basal cell carcinoma is characterized by local invasion, and only rarely metastasizes. The role of the containing basement membrane (BM) in this tumor is unclear. Several BM components have been shown to be absent or significantly reduced in BM surrounding infiltrating tumor.

OBJECTIVE

The purpose of this study is to examine the expression of epiligrin, a BM-associated glycoprotein, and the integrin chains alpha 3, alpha 6, beta 1, and beta 4 in the basement membranes surrounding basal cell carcinoma.

METHODS

Samples were obtained from 20 patients with basal cell carcinomas and subjected to a standard avidin biotin complex/alkaline phosphatase immunohistochemical technique using a panel of antibodies.

RESULTS

There was a consistent abnormality of expression of epiligrin, alpha 6, and beta 4.

CONCLUSION

We propose that reduced expression of epiligrin is involved in the pathogenesis of the local invasion by tumor and that an altered integrin ratio in basal cell carcinoma enhances tumor spread.

Differential expression of alpha 1(IV), alpha 2(IV), alpha 5(IV) and alpha 6(IV) collagen chains in the basement membrane of basal cell carcinoma

Type IV collagen, the major component of basement membrane, consists primarily of alpha 1(IV) and alpha 2(IV) chains. Recently, other types of collagen IV chains, i.e. alpha 3(IV), alpha 4(IV), alpha 5(IV) and alpha 6(IV) chains, have been identified by protein chemistry and molecular cloning. We have examined the diversity of the assembly of alpha (IV) chains of the basement membrane surrounding tumour nests of basal cell carcinomas, in tissues from 11 patients, by immunohistochemical analysis using specific monoclonal antibodies to six alpha (IV) chain. The immunostaining profile of each chain differed with respect to the histological subtypes of basal cell carcinoma. In the morphea-like subtype, which was more invasive, alpha 1(IV) and alpha 2(IV) chains were discontinuously stained, and alpha 5(IV) and alpha 6(IV) chains were entirely absent. However, in the superficial subtype, which was non-aggressive, alpha 1(IV), alpha 2(IV), alpha 5(IV) and alpha 6(IV) chains were well stained compared with the other subtypes of basal cell carcinoma. In addition, in the solid subtype, which showed slow growth and ulceration, alpha 1(IV) and alpha 2(IV) chains were continuously stained, and alpha 5(IV) and alpha 6(IV) chains were discontinuous or absent. The assembly of alpha 5(IV) and alpha 6(IV) chains into the basement membrane was inhibited in the solid and morphea subtypes of BCC. This differential expression of type IV collagen chains seems to be associated with the invasive potential of basal cell carcinoma.

Cell-type related and spatial variation in the expression of integrins in cutaneous tumors

Integrins constitute a group of transmembrane proteins which mediate cell-cell and cell-matrix interactions. Previous studies have shown both increased and decreased expression of integrins in relation to malignancy and invasion. In the present study, we investigated integrin distribution in cutaneous tumors by using monoclonal antibodies on frozen tissue sections. Antibodies to integrin subunits alpha v, alpha 3, alpha 4, alpha 5, alpha 6, beta 1 and beta 3 were used. The study was designed to explore (i) the association between integrin expression and the tumor type, and (ii) the effect on the integrin expression of the location of the tumor, i.e. whether it grows intraepidermally or within various compartments of the dermis (papillary or reticular). Beta 1, beta 3 and alpha 3 were strongly or moderately expressed in the epithelial and stromal cells of basal cell carcinomas (BCC), seborrheic keratoses, solar keratoses, dermatofibromas (DF), and showed a variable expression in the nevic cells of benign and dysplastic nevocellular nevi. alpha v and in alpha 5 appeared strongly expressed in the stromal cells of BCC and DF, while only a focal, often weak staining was seen in nevic cells and in the epithelial cells of BCCs. In some nevocellular nevi, they were only expressed, together with alpha 4, in the deep-seated nevic cells in the reticular dermis. alpha 6 was expressed by tumor cells of BCCs and nevocellular nevi only within the dermo-epidermal junction. In seborrheic keratosis and solar keratosis a basement membrane-associated staining pattern for alpha 6 was seen in the basal cell layer, with focal discontinuities in solar keratosis.(ABSTRACT TRUNCATED AT 250 WORDS)

The borderline: basement membranes and the transition from premalignant to malignant neoplasia

In this paper, the use of immunohistochemistry for the analysis of basement membrane components and related extracellular matrix proteins in human cancer is reviewed. Basement membranes in cancer are dynamic structures that are constantly degraded but also deposited, in close collaboration between tumor cells and stromal cells. Basement membrane immunohistochemistry, using antibodies against type IV collagen and laminin, appears to be a useful tool in the analysis of lesions on the borderline between premalignant and malignant. Basement membrane interruptions, however, cannot be used as the only criterion for the diagnosis of malignancy. Type VII collagen is often degraded prior to type IV collagen and laminin in early invasion. This protein also tends to be expressed in carcinomas when it is not found in the corresponding normal tissue. Tenascin seems to play a complex role in the development of human tumors, including promotion of cell growth and differentiation, cell migration during invasion, and tissue remodeling during the development of primary and metastatic lesions. Further systemic exploration of extracellular matrix molecules in neoplasms should yield new information relevant for cancer biologists and useful in cancer diagnosis.

Human ductal adenocarcinomas of the pancreas express extracellular matrix proteins

Pancreatic ductal adenocarcinomas are characterised by a dense connective tissue reaction. To test the hypothesis that stroma components are synthesised and produced by the tumour cells themselves, eight cell lines as well as six xenografted tumours from human ductal adenocarcinomas of the pancreas were examined for the expression of extracellular matrix proteins (ECM), using cDNA probes and antibodies to collagen types I, III and IV, vitronectin, fibronectin, undulin and laminin. All tumour cell lines (CAPAN-1, CAPAN-2, AsPC-1, BxPC-3, PANC-1, PaCa-2, PaCa-3, PaCa-44) and xenografted human pancreatic tumours expressed at least one of the examined ECM at the RNA (collagen type IV > laminin = fibronectin = vitronectin > collagen type III > undulin > collagen type I) or protein level (collagen type IV = collagen type III > vitronectin > laminin > collagen type I = fibronectin > undulin). In nude mouse tumours expression of laminin and collagen I was most pronounced in well-differentiated carcinomas. In a few tumours, collagen type III, vitronectin and undulin were expressed on the luminal side of the neoplastic glands, suggesting loss of normal polar differentiation. Incubation with fetal calf serum modulated ECM RNA levels to a varying extent in all but one cell line (AsPC-1). The results suggest that human pancreatic ductal adenocarcinomas cells are capable of synthesising and producing extracellular matrix proteins in vitro and in vivo, but that the extent and pattern of ECM expression differs between the various tumours and conditions tested.

Localization of 92-kDa type IV collagenase in human skin tumors: comparison with normal human fetal and adult skin

To investigate the role of secreted metalloproteinases in the behavior of skin tumors we have studied immunoreactivity for 92-kDa type IV collagenase (92T4Cl) in benign tumors of sweat glands, basal cell carcinomas (BCC), baso-squamous cell carcinomas (BSCC), and squamous cell carcinomas (SCC). In all tumors, the enzyme was found in stromal cells, but not in tumor epithelium. 92T4Cl-positive cells contained the common leukocyte antigen HLe-1(CD45) and the polymorphonuclear leukocyte-specific antigen PMN-8C7. Only a few 92T4Cl-positive cells expressed either macrophage-specific Leu-M5 or eosinophil-specific cationic protein antigens. In benign sweat gland tumors, and in the majority of nodulocystic and adenoid BCCs, 92T4Cl-positive cells were relatively rare and no extracellular deposition of the enzyme was found. In the more aggressive tumors examined, SCCs, BSCC, recurrent, infiltrative, and morpheaform BCCs, 92T4Cl-positive cells were very abundant. In addition, a significant quantity of extracellular enzyme was deposited both within the extracellular matrix adjacent to the tumor nests and in their basement membrane zone. In normal adult skin only a few scattered 92T4Cl-containing cells were found in the dermis whereas in fetal skin, groups of 92T4Cl-positive, HLe-1-negative cells were present in the upper dermis. These observations suggest that in cutaneous tumors, extensive infiltration of 92T4Cl containing polymorphonuclear leukocytes and the extracellular deposition of the enzyme in the basement membrane zone are signs of more aggressive tumor behavior.

Self limited dermal invasion of keratinocytes in maculopapular eruptions after systemic chemotherapy

Benign, multifocal, and transient (spontaneously disappearing within one month) stromal invasions of atypical basal keratinocytes were found in light and electron microscopic examination of maculopapular eruptions which developed after receiving an 8 day cycle of doxorubicin, 5-fluorouracil (5-FU), and cyclophosphamide (Cy) in a 63-year-old woman. She had had a modified radical mastectomy to remove a carcinoma of her right breast.

Clinicopathological and immunohistochemical study of basal cell carcinoma with reference to the features of basement membrane

One hundred and thirty-five cases of basal cell carcinoma (BCC) were investigated, focusing upon factors determining a postoperative prognosis. Out of the 135, nine tumors on the face recurred. All of these nine tumors were insufficiently extirpated at the initial operation, and showed micronodular or infiltrative patterns with stromal fibrosis. Dividing the degree of dermal invasion into four levels, all tumors with recurrence reached levels 3 and 4, the two deeper groups. The immunohistochemical study using anti-laminin and anti-type IV collagen antibodies showed various changes of staining pattern around tumor cell nests, such as attenuation, disruption, and thickening of basement membrane, in contrast with the normal thinly continuous staining around nontumorous control epidermis. The disruption of basement membranes was remarkable around the tumor cells showing a micronodular growth pattern, although the discontinuity of basement membrane was observed in all types of BCCs to a greater or lesser degree. Ultrastructural thickening, multiplication, or discontinuity of basement membranes were found in all 19 cases examined with a greater or lesser degree, although they were most frequently observed around the cell nests showing micronodular growth patterns. It was concluded that deep dermal and marginal invasions were the most ominous signs of recurrence of BCCs. Although the disruption of basement membranes might participate in the local aggressiveness of BCCs, especially in the tumor cells showing micronodular infiltrative growth, other factors may concern the recurrence of BCCs.

Urokinase plasminogen activator is immunocytochemically detectable in squamous cell but not basal cell carcinomas

The presence of plasminogen activators (PA) in a variety of solid tumors appears to correlate, in a number of instances, with enhanced invasive or metastatic capabilities. In the present study, we have immunocytochemically examined basal cell (BCC) and squamous cell carcinomas (SCC) comprising a spectrum of histologic subtypes for the presence of urokinase-type (uPA) and tissue-type (tPA) PA. Neither uPA nor tPA was noted in any BCC, whether of the nodular, infiltrative, morpheaform, or basosquamous variety. uPA but not tPA was seen in 12 of 16 SCC examined; the tumors lacking uPA were all histologically well differentiated. No relationship between uPA expression and depth of invasion was noted, and uPA was not preferentially expressed at tumor borders. We conclude that uPA presence in SCC may relate to the degree of differentiation.

The epidermal basement membrane in basal cell carcinoma: an immunohistochemical study

An immunohistochemical study of basal cell carcinomas of varying histological type, using a panel of antibodies to constituents of the epidermal basement membrane, showed marked deficiencies in the expression of the antigens identified by the antibodies LH7.2, GB3 and G71. There was no correlation between loss of immunoreactivity to these antibodies and the histological features of the tumour.

Acquired progressive lymphangioma

Acquired progressive lymphangioma is rare and can histologically mimic well-differentiated angioendothelioma. In a 9-year-old boy with acquired progressive lymphangioma, we demonstrated that the neoplasm consists of at least a vascular component and a smooth muscle component. The presence of type IV collagen around many vascular channels suggests that an intermediate stage of differentiation between blood vessels and lymphatics may be present. Our findings indicate that acquired progressive lymphangioma is most likely a complex hamartoma composed of vascular channels and smooth muscle.

Ultrastructural examination of experimentally induced premalignant lesions

Lesions induced in hamster cheek pouch using dimethylbenz(alpha)anthracene were studied by transmission electron microscopy and compared with normal tissue. Features regarded as suggestive of progression towards malignancy were: increased numbers of membrane-bound vesicles in basal cells, gaps in the lamina densa associated with widening of the lamina lucida and an irregular epithelial-connective tissue junction, the presence of cerebriform cells and frequent close association of 2 or more intra-epithelial cells (lymphocytes, cerebriform cells, Langerhans cells).

Biology of basal cell carcinoma (Part I)

Basal cell carcinoma is the most common malignancy in humans. Although rarely metastatic, it is capable of significant local destruction and disfigurement. This two-part article reviews the current understanding of basal cell carcinoma biology. Part I examines significant clinical, histologic, and ultrastructural features that relate to invasive potential. Genetic characteristics, including tumor growth rate, chromosomal abnormalities, and oncogene presence, are discussed, and expression of important cell and matrix proteins, including keratin, fibronectin, and HLA antigens, are reviewed. Further topics to be explored in Part II include host immunologic responses, theories of pathogenesis, and valuable second-line therapeutic regimens for treatment of multiple cancers.

Prognostic significance of laminin in adenocarcinoma of the lung

The distribution of laminin in tumor-associated basement membrane was immunohistochemically investigated in 115 cases of adenocarcinoma of the lung. The distribution of laminin was classified into continuous and discontinuous staining patterns. The incidence of the discontinuous pattern was less in early-stage disease than that in advanced stages (P less than 0.01). In patients with stage I, the incidence of discontinuous patterns was greater in short-term survivors than in long-term survivors (P less than 0.05). By contrast, in patients with stage III, the discontinuous pattern of laminin was frequently seen in both long-term survivors and short-term survivors, with no difference between the two groups. These data suggest that the discontinuous pattern of laminin in tumor-associated basement membrane reflects the spread and dissemination of tumor, hence a close relationship to the prognosis.

The subbasement membrane distribution of type IV collagen in normal human skin

Samples of normal human skin were obtained from 48 sites in 26 subjects ranging in age from 2 to 85 years. The samples were examined by indirect immunofluorescence and immunoelectron microscopy using anti-human type IV collagen antibodies produced by immunizing rabbits with type IV collagen extracted from human placenta. Fluorescence was observed as granular or fine fibrous patterns, not only in the basement membrane at the dermo-epidermal junction, around the vessels, and the accessory organs of the skin, but also in the dermal regions in the vicinity of the basement membranes. This suggests the presence of type IV collagen in the dermis deep to the basement membrane. Ultrastructurally, the extrabasal lamina distribution of type IV collagen was noted as a partial distribution around the fibroblasts that existed close to the basal lamina. These findings are considered to be important in examining the function of this collagen in the dermis and the dynamics and metabolism of the basement membrane under normal and abnormal conditions.

Defective expression of basement membrane-associated C3d,g in papulonodular basal cell carcinomas

Recent studies in our laboratory have shown that C3d,g, a 41,000-Da fragment of the third component of complement, is present along the base of the lamina densa and in the sublamina densa region of normal human epidermal basement membrane, but absent from the skin of a patient with congenital C3 deficiency. In studies of human skin, papulonodular basal cell carcinomas have served as a useful model for the investigation of various basement membrane antigens and matrix proteins. To further investigate the presence of C3d,g within epidermal basement membrane as well as examine its relationship with other known basement membrane constituents, we have analyzed serial sections of ten papulonodular basal cell carcinomas by light and immunofluorescence microscopy. In these studies, C3d,g was either absent (N = 9) or minimumly detectable (N = 1) in tumor nest basement membranes. While bullous pemphigoid and KF-1 antigens were absent (N = 6 and N = 3, respectively) or significantly decreased (N = 4 and N = 7, respectively), epidermolysis bullosa acquisita antigen was routinely present though somewhat (N = 3) or moderately decreased (N = 3). Laminin and type IV collagen were expressed normally in all tumor nest basement membranes. All constituents, including C3d,g, were present in adjacent normal epidermal basement membrane of these tumor samples. This study has demonstrated antigenic alterations within each ultrastructural subregion of papulonodular basal cell carcinoma tumor nest basement membranes by identifying the virtual absence of C3d,g (sublamina densa) as well as a significant reduction in KF-1 (lamina densa) and bullous pemphigoid (lamina lucida) antigens. Moreover, the presence of laminin, type IV collagen, and epidermolysis bullosa acquisita antigen in tumor nest basement membranes suggests that these particular constituents neither cleave C3 nor act as essential binding sites for passive incorporation of this complement component in epidermal basement membrane. These studies give additional support to the hypothesis that C3d,g is a previously unrecognized constituent of normal epidermal basement membrane and does not represent passive incorporation of circulating C3 at this site in human skin.

Structure of basement membranes in malignant melanoma and nevocytic nevi

Basement membranes found around tumor cells in nevocytic nevi, Spitz's nevi, and malignant melanomas were analyzed by electron microscopy and antibody staining for several basement membrane proteins. Nevocytic nevi and Spitz's nevi showed a distinct, occasionally discontinuous lamina densa regardless of whether they were located in junctional zones of the epidermis or within the dermis. All basement membranes around nests of aggregated nevus cells, however, lacked anchoring fibrils. This correlated with the absence of type VII collagen. In contrast, type IV collagen, laminin, and nidogen were present at the periphery of the nevus cell clusters in agreement with the presence of an intact lamina densa. Aggregated tumor cells in malignant melanomas were bordered by a lamina densa when located in a junctional position and lacked this structure when they had migrated into the dermis. This process was accompanied by a drastically reduced staining for collagen type IV and nidogen, whereas laminin was still detectable. Anchoring fibrils and their molecular correlate, type VII collagen, were consistently absent. These observations demonstrate major alterations in the composition of basement membranes around malignant melanomas, which can be an important factor for the invasive growth and formation of metastases of these tumors.

Morpheaform basal cell carcinoma in a young black woman

Basal cell carcinomas are uncommon in black patients, and morpheaform basal cell carcinomas are an uncommon histologic subtype. This case report describes the rare occurrence of a morpheaform basal cell carcinoma in a relatively young black patient. This patient underwent Mohs micrographic surgery as the primary therapy for this tumor. Some features of morpheaform basal cell carcinomas are reviewed, and basal cell skin cancer in blacks is discussed.

Histopathological and immunohistochemical changes in neurosurgically resected epileptic foci

Neurosurgical resection of an epileptic focus was performed in eleven patients suffering from drug resistant focal epilepsy. The clinical result was favourable in nine cases and corresponds to the earlier results. The routinely processed biopsy specimens obtained from the brain resections were stained with haematoxylin-eosin and with specific antisera to GFAP, S-100, NSE, laminin, and fibronectin using the peroxidase-antiperoxidase technique. The main pathological finding was gliosis in eight cases, neuronal degeneration in two cases, and a vascular malformation in one case. The anti-GFAP as a specific marker of astrocytes made the astroglial proliferation clearly visible, demonstrating an astroglial scar in four cases and a moderately to strongly increased amount of astroglial cells in another four cases. Anti-S-100 and anti-fibronectin are not as specific markers. They stained both neurones and glial cells with comparable results to that of anti-GFAP but with a lower specificity and sensitivity. Anti-NSE showed decreased amounts of neurones in most of the heavily gliotic lesions and also stained glial cells in some cases. Anti-laminin stained the pial and vascular basement membranes and revealed an increased vasculature in two cases. From these results, it appears that GFAP immunostaining is a highly demonstrative means for the visualization of astrogliosis in epileptic lesions and may be of help in identifying slight focal changes. An exact demonstration of neuronal loss or other neuronal changes still waits for a more specific marker than NSE. A favourable clinical outcome after neurosurgery seems to be associated with the patients showing a clearly gliotic brain lesion in one temporal lobe.

Peanut agglutinin immunohistochemistry of basal cell carcinoma

103 biopsies of basal cell carcinomas (BCCs) were studied using peanut agglutinin (PNA), PNA antibody and the peroxidase-antiperoxidase technique; 53 specimens of various skin tumors were examined as controls; 96% of the BCCs showed a band-like peritumorous reaction not seen in any other tumor except for the Pinkus' fibroepithelioma. The peritumorous PNA-binding was continuous in 51% of the BCCs studied and discontinuous in 45%; only 4% were completely negative. Both fibroepitheliomas revealed a discontinuous PNA-positive band. A narrow basement membrane-like positivity was seen around some small hair follicles situated within 2 neurofibromas and under one seborrhoeic keratosis. The PNA-binding band is apparently neither fibronectin, laminin, Type IV or Type V collagen and is not a constituent of normal epidermal, adnexal and vascular basement membranes.

Desmoplastic basal cell carcinomas possess unique basement membrane-degrading properties

Desmoplastic basal cell carcinomas (fibrosing or morphea types) were studied ultrastructurally, immunocytochemically, and biochemically for basement membrane-degrading activity and compared with the common varieties of basal cell (superficial and nodular-ulcerative types). Whereas the latter lesions demonstrated intact basement membranes as evidenced by extracellular laminin and type IV collagen immunoreactivity and the presence of an unusually thickened basal lamina, desmoplastic basal cell carcinomas showed large defects and absences in basal lamina and basement membrane immunoreactivity. Intense tumor cytoplasmic immunoreactivity for type IV collagenase was present in 13 of 15 cases of desmoplastic basal cell but absent in the superficial and nodular-ulcerative varieties. Whereas explant cultures of all the types of basal cell carcinoma studied gave rise to high levels of interstitial (type I) collagenase activity in conditioned media, only the desmoplastic variety exhibited high type IV collagenase activity. These findings suggest that the mechanisms by which the desmoplastic and the common varieties of basal cell carcinoma infiltrate host tissues may be fundamentally different.

Production of basement membrane laminin and type IV collagen by tumors of striated muscle: an immunohistochemical study of rhabdomyosarcomas of different histologic types and a benign vaginal rhabdomyoma

Immunohistochemical methods were used to demonstrate the distribution of basement membrane laminin and type IV collagen in eight tumors derived from striated muscle (three botryoid, two alveolar, and two adult-type rhabdomyosarcomas; one benign vaginal rhabdomyoma). All of the tumors produced significant amounts of both basement membrane components. Stainings clearly revealed the alveolar nature of the rhabdomyosarcomas, with the alveolar spaces surrounded by distinct basement membranes. Different stages of cellular development were identified in the botryoid sarcomas, with the most immature cells of the cambium layer devoid of external basement membrane around the tumor cells, although the stroma contained finely dispersed basement membrane material and some cells contained intracytoplasmic laminin or type IV collagen, indicative of the synthesis of these proteins. The more mature cells, which had abundant granular cytoplasm, were enveloped by distinct basement membranes and seemed to have coalesced, forming structures resembling myotubes. The adult-type rhabdomyosarcomas were composed of large pleomorphic cells that were surrounded by basement membranes, either individually or in small groups. Some giant cells contained intracytoplasmic laminin. The vaginal rhabdomyoma was composed of round rhabdoblastic cells or elongated strap cells with cross-striations. Cells of both of these types were surrounded by thin but distinct basement membranes. The results suggest that demonstration of basement membranes would be helpful in the diagnosis of tumors derived from striated muscle. The findings concerning different stages of maturation of tumor cells are in accordance with previous in vitro observations of myoblastic cells.

Immunohistochemical studies of basal cell carcinomas transplanted into nude mice

Xenografting into nude mice forms a system for analysis of human tissues under experimental conditions. In this study, normal skin samples and basal cell carcinomas were investigated, prior to and after transplantation, using immunofluorescence methods with antibodies against keratins, laminin, and collagen type IV. Three groups of transplants were studied: intact tissue samples, human epithelium (either normal or neoplastic) recombined with normal human dermis and, human epithelium recombined with normal mouse dermis. Transplants recovered after 3 weeks showed the following characteristics. The xenograft system was satisfactory in terms of host survival and rate of successful tissue recovery except for recombinants between human epithelium and mouse dermis. Intact and recombined samples of normal skin retained their preexisting patterns of architecture, cytodifferentiation, and basement membrane staining. Solid nonfibrosing basal cell carcinomas showed altered architecture and differentiation of both the epithelium and the basement membrane zone after transplantation: the solid tumor pattern changed towards spreading of tumor cells, a more squamous differentiation pattern was apparent and was confirmed by reactivity with antibodies against large keratins. Discontinuities of the basement membrane zone were detected with antibodies against laminin and collagen type IV. These changes were seen in both intact and recombined tumor transplants.

Basement membranes in experimentally induced skin tumors

Basement membrane changes in the epidermis and hair follicle apparatus resulting from topical 9,10-dimethylbenzanthracene applications were studied in mice, rats, and hamsters by light and electron microscopy and using antibodies to human collagen type IV and laminin. The basement membrane was distinct in epidermal hyperplasia, dysplasia, and papillomas, as well as around most of the keratoacanthomas and squamous cell carcinomas, which showed basement membrane irregularities, thickening, and reduplication in some areas. The invading edges of the squamous cell carcinomas with inflammatory infiltrates were devoid of laminin and collagen. Collagen IV and laminin-positive structures were observed around preserved follicular structures in rat: hair nevi and hair-follicle nevi, but partly absent around trichoepitheliomas and trichofolliculomas. Basal cell tumors were usually surrounded by a distinct basement membrane, which was lacking around some tumor cells.

Basement membrane proteins in the spleen: immunohistochemical demonstration and relation to reticulin

In the present study immunohistochemical staining has shown that the ring fibres of the human spleen contain the major basement membrane components, type IV collagen and laminin. The superiority of immunohistochemical methods in demonstrating basement membrane material in the spleen is emphasized. The results are compared with the demonstration of reticular fibres by Gomori's reticulin stain. The findings provide further information about the relationship between basement membrane material and reticular fibres in human spleen. The nature of splenic ring fibres is discussed in the light of the scientific literature.

Basement membrane structures in tumors of the ovary

The location and amount of the basement membrane (BM) components collagen IV and laminin were studied in ovarian epithelial, sex cord-stromal and germ cell tumors. BM structures were found in the epithelial stromal interface of benign surface epithelial tumors and, though discontinuous, around well-differentiated tumor islets, being less well developed in invasive undifferentiated neoplasms. The stromal components in Müllerian mixed tumors had less distinct BM structures, a finding useful for the classification of these neoplasms. Thecomas and fibromas had scanty collagen IV and laminin; granulosa cell tumors contained large amounts of BM material. A fine diffuse BM-positive pattern occurred in dysgerminomas and endodermal sinus tumors; BM structures in cystic teratomas were distinct. Collagen IV and laminin were well-developed in benign and slow-growing tumors with epithelial components and in their metastases, but less distinct in stromal tumors and highly malignant undifferentiated tumors, showing the usefulness of this method for the clinical and biological classification of such tumors.

Basement membrane in Kaposi's sarcoma: an immunohistochemical and ultrastructural study

Basement membranes were investigated in early angiomatous and late sarcomatoid stages of Kaposi's sarcoma (KS). Seven frozen skin biopsies of KS from five elderly Mediterranean people and one renal allograft recipient were labelled, using an immunoperoxidase technique, for basement membrane-specific macromolecules, laminin and type IV-collagen. Twenty-seven other frozen cutaneous lesions including haemangio and lymphangiosarcomas, benign vascular tumours, and various epithelial, melanocytic, fibrohistiocytic, fibrosarcomatous and muscular tumours were processed in the same way. In addition an ultrastructural study was performed in two cases of KS, one haemangiosarcoma and one lymphangiosarcoma. Intense labelling was observed for both type IV-collagen and laminin, which appeared closely co-distributed, in all areas of KS. Staining pattern was often regular and continuous around neoplastic vessels in early lesions of KS, as in benign vascular lesions, whereas in late nodular lesions large amounts of basement membrane components were present in intercellular spaces between densely aggregated spindle cells. In contrast, ultrastructural examination disclosed early disruption of basement membranes around neoplastic vessels, and occasional fragments of external lamina were seen at the interface between KS spindle cells and collagen. Similar results were obtained in angiosarcomas both by immunohistological and ultrastructural study. In the comparative group, laminin and type IV-collagen were present, in significantly fewer quantities and in various distinctive patterns, in epithelial, melanocytic, fibrohistiocytic and muscular tumors. This study deals with basement membrane modifications in early and late lesions of KS and provides further evidence in favour of the endothelial nature of the spindle cells of KS.

Immunoelectron microscope demonstration of the basement membrane components laminin and type IV collagen in the dermal cylindroma

Specific antisera to the human laminin P1 fragment and the 7S domain of type IV collagen were used to investigate the ultrastructural location of these main basement membrane (BM) components in a dermal cylindroma. Thick frozen sections were treated by the immunoperoxidase method, postfixed, embedded in epon and then sectioned for electron microscopic examination. Laminin and type IV collagen were detected in all layers of the cylindroma BM, together with non-specifically stained, diffusely distributed fibrillar structures, possible microfibrils and anchoring fibrils or residual stromal collagen fibres. The mixed presence of the BM components indicates that these substances codistribute rather than occurring as separate layers even when forming neoplastic basement membranes.

Basement membranes in cancer

Basement membranes are ubiquitous tissue constituents which occur as supportive structure adjacent to epithelium, endothelium, mesothelium and also around smooth as well as striated muscle cells, Schwann cells and fat cells. In various types of cancer, basement membranes have been extensively studied by electron microscopy. Often basement membrane interruptions were seen in invasive neoplasms but in some tumors the neoplastic cells were surrounded by a continuous basal lamina. Recent immunocytochemical studies have shown that in invasive carcinomas the neoplastic cells often lack a continuous basement membrane. This may be caused by catabolic activity of invasive tumor cells, which have been shown to produce specific collagenases, or by insufficient production and/or extracellular assembly of basement membrane components by the neoplastic epithelial cells. In diagnostic histopathology, immunocytochemical staining of basement membrane components such as type IV collagen and laminin may help to distinguish between noninvasive (benign or in situ) and invasive lesions. Furthermore, in carcinomas the extent of the expression of basement membrane components may be correlated with the degree of differentiation of the neoplastic cells. Finally, in soft tissue tumors, basement membrane staining may be helpful for the differentiation of basement membrane producing neoplasms (e.g. of vascular, neural, smooth muscle or striated muscle origin) from non-basement membrane producing neoplasms (e.g. of fibroblastic origin).