The biology of basal cell carcinoma: a review

Immunohistochemical expression of cytokeratin 15, cytokeratin 19, follistatin, and Bmi-1 in basal cell carcinoma

BACKGROUNDS

Basal cell carcinoma (BCC) is the most common cutaneous neoplasm. Despite numerous previous studies, the origin of BCC is still controversial.

OBJECTIVE

The aim of this study is to evaluate whether BCC arises from the hair follicle rather than the epidermal basal cell.

METHODS

The labeling index and differences of expression of the immunohistochemical (IHC) stainings of CK15, CK19, follistatin, and Bmi-1 were evaluated in 20 cases of BCC, 13 cases of trichoblastoma, 21 cases of actinic keratosis (AK), and 19 cases of squamous cell carcinoma (SCC) which were biopsied in the department of dermatology of the Yeungnam University Medical Center.

RESULTS

For CK15, labeling indexes of BCC (83.0%) and trichoblastoma (84.4%) were significantly higher than those of AK (15.9%) and SCC (15.8%). For CK19, labeling indexes of BCC (8.1%), trichoblastoma (6.6%), AK (3.5%), and SCC (14.8%) revealed no difference. For follistatin, labeling indexes of BCC (51.1%) and trichoblastoma (70.1%) were significantly higher than those of AK (0.9%) and SCC (8.5%). For Bmi-1, labeling indexes of BCC (74.4%) and trichoblastoma (84.7%) were significantly higher than those of AK (24.7%) and SCC (18.6%).

CONCLUSION

In this study, strong positivity of CK15, follistatin, and Bmi-1 was more frequently observed in BCC and trichoblastoma than in SCC and AK. These findings suggest that BCC and trichoblastoma share the same differentiation toward the hair follicle. Furthermore, CK15, follistatin, and Bmi-1 can be useful as markers to differentiate BCC from SCC.

Basal cell carcinoma of the skin (part 1): epidemiology, pathology and genetic syndromes

Basal cell carcinoma (BCC) is the most common skin cancer worldwide with increasing incidence, but difficult to assess due to the current under registration practice. Despite the low mortality rate, BCC is a cause of great morbidity and an economic burden to health services. There are several risk factors that increase the risk of BCC and partly explain its incidence. Low-penetrance susceptibility alleles, as well as genetic alterations in signaling pathways, namely SHH pathway, also contribute to the carcinogenesis. BCC associate with several genetic syndromes, of which basal cell nevus syndrome is the most common.

Basal Cell Carcinoma of the Sole

We report a case of a 72-year-old woman with a two year history of a plantar lesion. The clinical appearance, a nodular reddish irregular mass about 2 centimeters in diameter, suggested a tumoral lesion. Histologic examination revealed a basal cell carcinoma. The lesion was excised with no recurrence after two years of follow up. The clinical events, and the histological findings are briefly discussed.

Basal cell carcinoma: stressful life events and the tumor environment

CONTEXT

Child emotional maltreatment can result in lasting immune dysregulation that may be heightened in the context of more recent life stress. Basal cell carcinoma (BCC) is the most common skin cancer, and the immune system plays a prominent role in tumor appearance and progression.

OBJECTIVE

To address associations among recent severe life events, childhood parental emotional maltreatment, depression, and messenger RNA (mRNA) coding for immune markers associated with BCC tumor progression and regression.

DESIGN

We collected information about early parent-child experiences, severe life events in the past year as assessed by the Life Events and Difficulties Schedule, depression, and mRNA for immune markers associated with BCC tumor progression and regression from patients with BCC tumors.

SETTING

University medical center.

PARTICIPANTS

Ninety-one patients with BCC (ages, 23-92 years) who had a previous BCC tumor.

MAIN OUTCOME MEASURES

The expression of 4 BCC tumor mRNA markers (CD25, CD3ε, intercellular adhesion molecule 1, and CD68) that have been linked to BCC tumor progression and regression were assessed in BCC tumor biopsy specimens.

RESULTS

Both maternal and paternal emotional maltreatment interacted with the occurrence of severe life events to predict the local immune response to the tumor (adjusted P = .009 and P = .03, respectively). Among BCC patients who had experienced a severe life event within the past year, those who were emotionally maltreated by their mothers (P = .007) or fathers (P = .02) as children had a poorer immune response to the BCC tumor. Emotional maltreatment was unrelated to BCC immune responses among those who did not experience a severe life event. Depressive symptoms were not associated with the local tumor immune response.

CONCLUSIONS

Troubled early parent-child relationships, in combination with a severe life event in the past year, predicted immune responses to a BCC tumor. The immunoreactivity observed in BCCs and the surrounding stroma reflects an anti-tumor-specific immune response that can be altered by stress.

Nodular basal cell carcinoma is associated with increased hyaluronan homeostasis

BACKGROUND

Basal cell carcinoma (BCC) is one of the most frequent forms of malignancy in humans. Although BCC is a tumour of low degree of malignancy, if left untreated, it can be locally aggressive, eat away at tissues and cause ulceration. Nodular is the most common subtype of BCC (>50%). Although apparently non-invasive, micronodular, a certain subgroup of nodular, is likely to recur. Glycosaminoglycans (GAGs), such as hyaluronic acid (HA), are extracellular matrix molecules of high importance in malignant transformation, metastasis and other complex remodelling processes.

OBJECTIVES

To investigate the expression of GAGs and their metabolizing enzymes in nodular BCC, when compared with adjacent healthy human skin tissue specimens.

METHODS

Total GAGs were isolated and purified from nodular BCC and normal adjacent human skin tissue specimens. GAGs were subsequently fractionated by electrophoresis on cellulose acetate membranes and characterized using specific GAG-degrading enzymes. The content of HA in total GAGs was measured using ELISA and the expression of HA synthases (HAS), hyaluronidases (HYAL) and HA receptors (CD44 and receptor hyaluronic acid-mediated motility (RHAMM) was assessed using RT-PCR.

RESULTS

Nodular BCC is associated with increased levels of HA concomitant with upregulation of gene expression of HAS3, HYAL3 and RHAMM, when compared with normal adjacent skin.

CONCLUSION

These results indicate that HA homeostasis in nodular BCC shows distinct features which may be helpful in understanding the complex behaviour of nodular subtype of BCC, thus eventually leading to new treatment strategies.

Basal cell carcinoma in outdoor versus indoor workers in Turkey

BACKGROUND

Basal cell carcinoma remains a significant health problem, and is most common in people of Caucasian origin with significant sun exposure. This study investigated differences between two groups of Turkish patients with basal cell carcinoma: indoor workers versus outdoor workers.

METHODS

One hundred and twenty-one patients with primary basal cell carcinoma were categorized as outdoor (Group OW) or indoor workers (Group IW), according to sun exposure at work. Findings for age, sex, skin type, tumor location, and histologic subtype/aggression were compared.

RESULTS

The mean age of Group IW was lower than that of Group OW (57.3 +/- 9.2 vs. 65.8 +/- 12.2 years, respectively). Group OW comprised more men than women (63.4% vs. 36.6%, respectively), whereas women predominated in Group IW (62% vs. 38%, respectively). The facial cheek was a more frequent tumor site in Group IW than in Group OW (20% vs. 7.0%, respectively). There were no statistical differences with respect to skin types or histological subtypes; however, Group OW had a higher proportion of aggressive subtypes than Group IW (25.4% vs. 10%, respectively).

CONCLUSIONS

The results in the Turkish population of the study suggest that basal cell carcinoma may develop in indoor workers (intermittent sun exposure) earlier than in outdoor workers with chronic sun-exposure, but more aggressive subtypes are more likely to be linked with chronic sun-exposure.

The stromal reaction in basal cell carcinomas. A prerequisite for tumour progression and treatment strategy

Specimens of basal cell carcinomas collected from 28 patients were classified into three groups: superficial, nodular, and infiltrative, according to their microarchitecture. The specimens were then subjected to histological characterization by means of a biotinylated hyaluronan-binding probe (HABP). By using Ki-67 and PCNA the proliferative activity of the BCC tumours was evaluated with immunohistological techniques. In superficial BCC the tumour islands displayed moderate hyaluronan (HA) staining. Feeble proliferation, denoted by modest mitotic activity and weak Ki-67 and PCNA immunoreactivity, occurred within the tumour islands. The surrounding connective tissue resembled normal skin, and no differentiated tumour stroma was observed. In nodular BCC, the HA staining of the tumour strands was weak to moderate, denoting increased proliferative activity. The differentiated surrounding tumour stroma stained strongly for HA. Tumour islands of infiltrative BCC stained weakly to moderately to HA and evidenced intense proliferation. The intensely HA-stained tumour stroma ended abruptly and the adjacent areas were almost devoid of HA. This study showed that the proliferative activity of BCC cells is associated with increased expression of HA in the tumour stroma. Modification of tumour-associated connective tissue indicates a close relationship between the tumour cells and the adjacent matrix. In particular, in infiltrative BCC, such alterations include degeneration and possible modification and remodelling of the surrounding extracellular matrix. These processes involving areas of probable importance for tumour progression, should be considered when deciding the extent of intended surgical resection.

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.

Multiple basal cell carcinomas associated with hairy cell leukaemia

We report the case of a caucasian woman who, between the ages of 49 and 51 years, developed multiple (> 20) basal cell carcinomas (BCC). There was no family history of BCC. No abnormalities in the human homologue of the Drosophila segment polarity gene patched (PTCH), glutathione S-transferases T1 and M1, or cytochrome P450 1A1 were detected by polymerase chain reaction (PCR)-based molecular analysis. There was, however, actinic damage of the skin in sun-exposed areas. The patient was diagnosed as having hairy cell leukaemia (HCL) at the age of 51 years, based upon leucocyte morphology as assessed by light and electron microscopy, tartrate-resistant acid leucocyte phosphatase (TRAP) staining, fluorescence activated cell scanning of peripheral blood leucocytes and bone marrow histology. As the leukaemia slowly progressed over a 3-month period, the patient developed four further BCCs. Given that HCL is characterized by a profound defect in T-cell function, it is conceivable that T-cell immune dysregulation can contribute to the pathogenesis of BCC, possibly enhancing the aetiological effect of ultraviolet irradiation.

Infiltrative basal cell carcinoma occurring in sites of biopsy-proven nodular basal cell carcinoma

Over 200 basal cell carcinomas (BCCs) are biopsied and subsequently excised each year at the Veterans Affairs Palo Alto Health Care System (VAPAHCS). A focal infiltrative pattern developed in the region of the biopsy scar in the re-excision specimens of 20 cases out of approximately 400 BCCs (< 5%) examined histopathologically over a 2-year period. The patient population included predominantly male, elderly Caucasians (mean age 71), and all tumors fulfilled clinical and histologic criteria for nodular BCC at the time of initial punch or shave biopsy. No patient showed recurrence of tumor following simple re-excision with 2-3 mm surgical margins, with a mean follow up of 25.4 months after excisional surgery. These neoplasms had a more benign clinical course, possibly related to scar formation in healing sites of previously biopsied nodular BCC, rather than true aggressive-growth BCC. The authors conclude that a focal infiltrative pattern in a re-excision specimen may occur histologically as a scar-induced pattern which mimics an aggressive-growth BCC, but does not appear to have the same prognosis. We believe this is an important histologic observation, as recognition of biopsy scar changes in an excisional specimen of BCC may help to distinguish it from true aggressive-growth BCC.

Ovine squamous cell carcinoma: immunocharacterisation of neoplastic cells and peritumoural cellular infiltrate

An immunohistochemical characterisation of neoplastic cells and peritumoural cellular infiltrate of ovine squamous cell carcinomas (OSCC) in different stages of growth was carried out using a commercially-available panel of seven antibodies, and formalin-fixed and paraffin-embedded tissue samples. Neoplastic cells reacted with the anti-keratin monoclonal antibody RCK-102 and with an anti-keratin polyclonal antibody, whereas they were unreactive with the anti-keratin monoclonal antibody NCL-5D3. The tumour cells were unreactive with the anti-vimentin polyclonal antibody. Increased numbers of CD3+ T-lymphocytes, IgG-containing plasma cells and lysozyme+ macrophages were associated with precancerous lesions (actinic keratosis) and with early OSCC. These results show that early lesions of OSCC induce an in situ cellular and humoral immune response. In advanced OSCC, the number of CD3+ T-lymphocytes and macrophages in the peri- and intratumoural cellular infiltrate remained high, whereas a significant decrease of IgG-containing plasma cells was found compared with early OSCC. This finding suggests an in situ decrease in the humoral immune response in advanced OSCC.

Basal cell carcinoma in Qatar

BACKGROUND

There is an increasing incidence of basal cell carcinoma (BCC) and skin cancer in general among various countries, where the sun is implicated as an important causative factor.

METHODS

Results of clinical and histopathologic examination and the incidence rate of BCCs were recorded over a period of 5 years at Hamad Medical Corporation, Doha, Qatar.

RESULTS

Basal cell carcinoma is the commonest skin cancer in Qatar. The average annual incidence per 100,000 residents of working manpower, standardized to the 1986 census, is 9.9 for both sexes and at all ages. Expatriates formed the highest proportion and of these, Europeans were predominant. The tumor was more frequent in men, on sun-exposed areas, was mostly of the nodular and infiltrative type, and occurred in the 3rd, 4th, and 5th decades. As a whole, persons with relatively heavily pigmented skin constituted 66.7% of the patients.

CONCLUSIONS

Intense sunlight exposure during outdoor work and leisure activities in Qatar puts residents at increased risk for nonmelanoma skin cancer, even in persons with relatively pigmented skin.

Immune-associated cells in basal cell carcinomas of skin

Increased numbers of mast cells (MCs) and lymphocytes infiltrating in basal cell carcinomas (BCCs) have been observed. The presence of these infiltrating cells has been considered a sign of an immunologic anti-tumor response in the host, but the relationship of these two cell populations has not been examined. To elucidate this possible relationship, 30 non-ulcerated BCCs were analyzed. Frozen sections of the tumors were stained with monoclonal antibodies for Langerhans' cells, lymphocyte subsets and natural killer cells. Fluorescein isothiocynate (FITC)-avidin as well as anti-tryptase and anti-CD45RO monoclonal antibodies were used on formalin-fixed, paraffin-embedded sections for mast cell and T cell identification, respectively. B cells and natural killer cells were rarely observed in these tumors. MCs and T cells were quantified by direct enumeration and expressed as number of cells per high power field (hpf). FITC-avidin and anti-tryptase antibodies were equivalent in their ability to identify MCs. MC content in BCCs ranged from 1.0 to 31 cells/hpf. The number of T cells ranged from 0 to 50 cells/hpf with helper/suppressor cell ratios of 0.2 to 10. There was no correlation between helper/suppressor ratios and mast cell numbers; however, an inverse relationship was observed between the numbers of T cells and the number of mast cells in these tumors. These studies indicate that T cells and MCs are the primary immune cell populations responding to BCCs, and that decreased numbers of T cells are associated with more aggressive tumors.

Basal cell carcinoma and lifestyle characteristics

BACKGROUND

A number of lifestyle factors are important in the etiology of basal cell carcinoma. Previous studies have investigated smoking, alcohol, diet, and sun exposure as possible contributing factors. No previous studies have investigated case-controlled lifestyle influences in basal cell carcinomas referred for Mohs micrographic surgery.

METHODS

Cases were obtained from Mohs-referred basal cell carcinoma patients. Matched controls were selected from a busy dermatology clinic. The only criteria for selection of controls was never having had cancer previously. Cases and controls were surveyed regarding lifestyle characteristics.

RESULTS

Forty-six age, sex, and skintype-matched controls were compared. Sun exposure, alcohol, and smoking were not significant factors. Dietary fat, fiber, and the vitamins A, C, and beta carotene, as well as selenium showed important, but not significant differences. Caffeine consumption was higher in the cancer group.

CONCLUSIONS

Our findings agree with previously published studies in regard to antioxidant consumption as a protective factor for basal cell carcinoma. Caffeine consumption was higher in the cancer patients.

Basal cell carcinoma of the scalp resulting in spine metastasis in a black patient

Basal cell carcinoma (BCC), the most common skin cancer in the United States, is locally invasive but has a low risk of metastasis. BCC is rare in black patients but, regardless of racial origin, most BCC occurs on sun-exposed areas. We describe a 67-year-old black man with a large BCC on the hairy scalp, a relatively sun-protected area, that metastasized to the spine. To our knowledge, this is the first description of a black patient with development of metastatic BCC on an otherwise normal scalp.

Regression in basal cell carcinoma: an immunohistochemical analysis

Spontaneous regression of some cutaneous tumours is well recognized, and is thought to result from an immunological response to the tumour. Regression has previously been noted in basal cell carcinomas, but no studies defining the role of the immune response in the regression of this malignancy have been performed. We have examined 45 primary basal cell carcinomas (BCCs) (20 nodular, 25 superficial) and identified the cellular phenotypes and activation states of the cells infiltrating primary regressing and non-regressing BCCs, by immunocytochemistry. We have found a significantly increased number of CD3+ and CD4+ T cells infiltrating regressing compared with non-regressing tumours, and the expression of interleukin-2 receptor (an early activation marker for T cells) was also increased. There were no significant differences in class II major histocompatibility complex (MHC), CD1, or macrophage antigen expression in these groups. These findings suggest that activated CD4+ cytokine-secreting cells are important in the regression of BCCs.

Basal cell carcinoma of the eyelid and periocular skin

Basal cell carcinoma is the most common human malignancy. This locally invasive tumor rarely metastasizes, but can cause considerable morbidity when on the eyelids and periocular skin. The successful management of BCC requires an awareness of its broad clinical spectrum and knowledge of the risk factors associated with therapeutic failure. The optimal therapy for basal cell carcinoma is controversial. Treatment strategy is formulated on an individual basis, taking into account tumor size, anatomic location, and growth pattern. The immune status and life expectancy of the patient also must be considered. While complete eradication of the tumor is desirable, this can be challenging since basal cell carcinomas often extend beyond their apparent clinical margins. Since prevention is preferable to treatment, the public needs to be informed that the incidence of periocular skin cancers can be reduced with the longterm use of sunscreens, sunglasses, and hats with brims.

Immunohistochemical evaluation of epidermis overlying basal cell carcinomas

We have examined the character and carcinogenic properties of the normal-appearing epidermis overlying basal cell carcinomas by immunohistochemical methods, employing a series of monoclonal antibodies. The labelling index was significantly increased in the atrophic epidermis overlying basal cell carcinomas (solid type, n = 20), compared with the epidermis overlying or adjacent to squamous cell carcinoma (n = 20), keratoacanthoma (n = 10), dermatofibroma (n = 10), neurofibroma (n = 10), soft fibroma (n = 10), pyogenic granuloma (n = 10) and cutaneous leiomyoma (n = 5). Cells which expressed epidermal growth factor (EGF) receptor were detected in all layers of the epidermis over the basal cell carcinomas, but not the other tumours. Basement membrane-related antigens, including bullous pemphigoid antigen and GB3 antigen, were decreased in the epidermis. AE1, the monoclonal antibody against basal cell keratin, reacted with the uppermost layers of the normal-appearing epidermis overlying the basal cell carcinomas. ICAM-1 expression was very weak in the overlying epidermis. The dermis subjacent to the proliferating epidermis showed staining for transforming growth factor-alpha (TGF-alpha), strong positive PECAM-1 staining of endothelium, and numerous HLA-DR-positive cells. From these results, we suggest that the proliferative activity in the epidermis overlying basal cell carcinomas is not a state induced by the dermal infiltrate, but represents carcinogenic activity of the epidermis.

Basal cell carcinoma in young adults

The epidemiology and outcome of basal cell carcinoma (BCC) in adults aged 15-34 years were examined. Northern Region Cancer Registry data from 1979 to 1989 revealed a crude annual incidence of 37/100,000 total population and the incidence was constant in all age-groups during this period; 150 patients (1.2%) were aged 15-34 years. There was a small excess of females in the young age-group. The outcome of BCC in young adults was determined using records of all patients registered over 5 years ago and additional information from family doctors where required. Patients with BCC in naevus sebaceous or with syndromes of which BCCs are a feature were excluded. Median duration of BCC pre-diagnosis was 3 years. Of 39 patients with completed 5-year follow-up data, 21% had either incomplete excision requiring further early treatment (n = 4), a later local recurrence (n = 2), metastatic BCC (n = 1) or a subsequent further primary tumour (n = 1); an additional three patients had two primary tumours at initial presentation. Median hospital follow-up was 12 months but the apparent disease-free interval in patients with recurrent or new BCC was frequently over 2 years. BCC in young adults may not be suspected because it is uncommon. However, the high frequency of local recurrence and of multiple primary tumours indicates that careful follow-up is prudent in young patients with this tumour.

The histopathology of the skin basal cell carcinoma with areas of intermediate differentiation. A metatypical carcinoma?

The histopathology of the skin basal cell carcinomas (BCCs) with areas of intermediate differentiation (ID) has been investigated. In a series of 127 BCCs, areas of ID were found in 28 tumors (22%), and also in an additional 10 cases of other series. These areas consisted of compact masses of cells without peripheral palisading, and with intermediate differentiation between basal and squamous cells. In comparison with the common undifferentiated BCCs, the BCCs with the ID areas may behave in a more aggressive fashion, since they displayed more precocious ulceration in small tumors (p less than 0.001), greater infiltrative features (p less than 0.001), more atypical cells (p less than 0.001) with increased nuclear-cytoplasmic ratio and more mitoses (p less than 0.001). The relation of such basal cell carcinomas to the metatypical carcinoma of the skin was discussed. Metatypical carcinoma, however, has been poorly defined and thus has no general acceptance in the literature. The new definition of the basosquamous cell carcinoma and the presence of intermediate areas of differentiation in this tumor were emphasized, and it was suggested that metastatic basal cell carcinoma and metatypical carcinoma may be the same tumor.

In-vitro DNA synthesis of keratinocytes in normal human skin, psoriasis, seborrhoeic keratosis, Bowen's disease and basal cell carcinoma

The DNA-synthesizing cells in benign and malignant keratotic diseases including psoriasis, seborrhoeic keratosis, Bowen's disease and basal cell carcinoma were studied. Cells in S-phase were labelled after small pieces of the lesions were incubated in tissue culture medium that contained 5-bromo-2'-deoxyuridine (BrdU). The labelling of DNA was analysed using the labelling index and pattern. Although the malignant diseases tended to show a higher DNA labelling index, neither this nor the loss of polarity alone was associated with malignancy. However, a higher DNA labelling index together with a loss of polarity was characteristic for malignancy.

The expression of skin-specific gene K51 in the epidermal layer of human skin and in basal cell carcinoma cells

Gene K51 probe isolated previously from the rat genomic library has been used to study the expression of its human counterpart by in situ hybridization and Northern blot analysis. A polyA-containing transcript of human gene K51 of 3 kb size has been detected in embryonic skin. The gene is also expressed in the epidermis of newborn humans and adults, but not in the adjacent mesenchymal tissues. Immunostaining with keratin antisera revealed predominantly earlier stage expression of K51 than cytokeratin markers. Sebaceous and sweat glands also contain cells expressing K51 gene. K51 expression was found in the cells of eight individual basal cell carcinomas tested, with the level of expression lower than in keratinocytes from normal human epidermis. We propose that K51 gene expression could serve as a convenient marker for the study of the process of skin keratinocyte development and the changes in this process associated with skin cancers and dysplasia.

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.

Immunohistochemical differentiation of basal cell epithelioma from cutaneous appendages using monoclonal anti-glycoprotein antibody TNKH1. Its application in Mohs' micrographic surgery

TNKH1, which was primarily developed to detect differentiated melanocytic tumor cells, was found to recognize basal keratinocytes of hair follicle and some basal keratinocytes of human epidermis. Thus, TNKH1 decorated the basal cells of following structures: epidermis (39 of 54, only part of each specimen [OPES]), upper hair follicle (one of 24, OPES), lower hair follicle (21 of 21, very high rate of each specimen [VHES]), sebaceous duct (14 of 15, VHES), sebaceous gland (ten of 14, germinative cells near duct), eccrine duct (three of 19, OPES). Epithelial tumors, considered to be derived from or differentiating toward hair follicle such as trichilemmoma (one of one, VHES) and basal cell epithelioma (BCE) (32 of 32, VHES) were labeled not only in the peripheral cells but in their entirety. On the other hand, epidermal tumors, such as seborrheic keratosis (ten of 11, OPES), actinic keratosis (two of three, OPES), and squamous cell carcinoma (one of two, OPES), showed an irregular peripheral basal cell staining as in normal epidermis. The apocrine sweat apparatus and eccrine secretory portion were negative. Eccrine ductal tumors such as syringoma (two tested), eccrine acrospiroma (one), and eccrine carcinoma (two) were TNKH1 negative. Taking advantage of this total labeling of BCE versus peripheral labeling of the hair follicle, the authors could distinguish BCE tissue from other structures clearly. Among confusing structures the upper hair follicle and the eccrine duct were excluded easily because of their negative staining with TNKH1. The lower hair follicle was TNKH1 positive but only in the outer basal layer, whereas the BCE was TNKH1 positive in its entire basaloid cells. The result indicated that TNKH1 will be a useful antibody in Mohs' micrographic surgery.

Embryologic fusion planes and the spread of cutaneous carcinoma: a review and reassessment

It has long been held that embryologic fusion planes influence the spread of skin cancer. Embryologic fusion planes have been implicated in the depth of invasion, horizontal spread, and recurrence of cutaneous carcinoma. However, these structures have never been studied in detail. A review of the surgical literature reveals considerable confusion regarding the exact nature, location, and tumor interactions of these fusion planes. We review the gross and microscopic development of sites of embryologic fusion. We examine histologic sections through fusion sites in normally developed adult and fetal fresh cadaver specimens. Our studies, supported by our review of developmental anatomy, indicate that fusion planes do not persist as identifiable anatomic structures that would influence tumor spread.

Comparative morphometric analysis of aggressive and ordinary basal cell carcinoma of the skin

A morphometric analysis was performed on histologic sections of 11 cases of aggressive basal cell carcinoma that recurred and/or metastasized after the first diagnosis (BCC2) and on 11 ordinary basal cell carcinomas (BCC1). The considered parameters were as follows: nuclear area, perimeter, maximum diameter, feret x, feret y, form perimeter, and form area. The results show numeric differences between the two groups for the first five parameters. A statistical analysis was performed between BCC1 and BCC2 for all the considered parameters using a two-sided t test for independent samples. The test showed significant differences between the first five parameters except for the two form factors. A multivariate analysis was performed using area and perimeter values of the compared groups that amplified the discrimination threshold between the two groups. The authors conclude that a morphometric assessment may bring significant contribution in the knowledge and in the outcome prediction of basal cell carcinoma.

Flashlamp-pumped pulsed dye laser therapy for poikiloderma of Civatte

The use of pulsed yellow light from a flash-lamp-pumped pulsed dye laser has provided a successful form of therapy to remove both the telangiectasias and irregular pigmentation associated with poikiloderma of Civatte. The short pulse duration and specificity of the interaction between yellow light and hemoglobin permit this technique to be performed on the thin skin of the neck without textural changes or scarring. Furthermore, use of the large beam diameter of this laser system allows for rapid treatment of large areas in a short period of time.

Carcinoembryonic antigen in basal cell neoplasms in black patients: an immunohistochemical study

The development of skin cancer in black persons is rare, and basal cell epitheliomas are the most uncommon. Eight tumors were evaluated by routine histochemistry examination and immunoperoxidase staining for carcinoembryonic antigen (CEA). Our results demonstrate that half these tumors showed a positive reaction to this antigen, supporting the adnexal origin/differentiation of these lesions. Sixteen (16/18) similar tumors from white patients failed to show equivalent features. In addition, some of these CEA-positive tumors seem to demonstrate less aggressive behavior.

Penile basal cell carcinoma. Report of a case and review of the literature

We describe a 69-year-old man with penile basal cell carcinoma and review the literature on this condition. Basal cell carcinomas of the penis are rare, and there are only 26 other reported cases. There is no documented case of metastatic penile basal cell carcinoma. The one reported case of metastatic penile basal cell carcinoma actually represents urethral transitional cell carcinoma. Therefore conservative therapy with local removal is adequate treatment, and more extensive procedures are unnecessary. Ultraviolet light exposure may be an important etiologic factor for basal cell carcinomas located on sun-exposed areas. The occurrence of basal cell carcinomas on non-sun-exposed areas raises the possibility of other, not yet defined, etiologic agents.

Cutaneous diseases preceding diagnoses of lymphoreticular malignancies

Dermatology visits during a 5-year period before the diagnosis of lymphoreticular malignancy in 258 subjects were reviewed and compared with visits made by 258 randomly selected, age- and sex-matched control subjects in the same period. Six of the 96 patients with leukemia and none of their matched controls (p less than 0.05) had cutaneous malignancies 20 to 60 months before the diagnosis of leukemia. There was no increase in cutaneous malignancies preceding lymphoma. A common factor predisposing to both cutaneous malignancy and leukemia, such as a defect in immunosurveillance, is suggested.

An absence of human leukocyte antigen-DR and a decreased expression of beta 2-microglobulin on tumor cells of basal cell carcinoma: no influence on the peritumoral immune infiltrate

The expression of human leukocyte antigen-DR (HLA-DR) and beta 2-microglobulin on the tumor cells and their correlation (if any) to the degree and the composition of the peritumoral mononuclear infiltrate were studied in 37 basal cell carcinomas from 32 patients with an indirect immunoperoxidase technique. In 36 of 37 basal cell carcinomas (97%) there was no expression of HLA-DR on tumor cells of basal cell carcinoma. In 13 of 37 basal cell carcinomas (35%) beta 2-microglobulin was expressed on the tumor cells. Both a diffuse cytoplasmic and a membrane staining were observed in only six of these 13 basal a diffuse cytoplasmic and a membrane staining were observed in only six of these 13 basal cell carcinomas; in the other seven basal cell carcinomas only a diffuse cytoplasmic staining was observed. In all 37 basal cell carcinomas there was membrane staining for beta 2-microglobulin in the normal epidermis. The intensity of staining in the normal epidermis was always stronger than that in the tumor nests. There was a varying degree of peritumoral immune infiltrate in all basal cell carcinomas. It comprised mainly T cells (mean percentage 57 +/- 15). In the group of patients with basal cell carcinoma with moderate to heavy infiltrate the mean percentage of T cells was 63 +/- 13, which was significantly higher than the mean percentage of T cells (46% +/- 14%) in the group of patients with basal cell carcinoma with a mild infiltrate. This difference was mainly the result of an increase in T helper cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Rapid development of metastases from basal cell carcinoma presenting as cranial nerve palsies

A case is reported of metastatic basal cell carcinoma presenting with multiple neurologic deficits 20 months after excision of the primary lesion with good local control. Many features associated with the development of metastasis from basal cell carcinoma were not present in this case.

AIDS-associated Kaposi's sarcoma: variables associated with survival

The records of 187 consecutive patients with acquired immunodeficiency syndrome (AIDS)-associated Kaposi's sarcoma were analyzed retrospectively for a number of prognostic variables. In a multivariate analysis, the initial site of disease was found to be related to survival. Initial lesions on the skin of the lower extremities or in the lymph nodes were associated with longer survival (p = 0.005 and p = 0.01, respectively). Higher helper/suppressor T cell ratios were strongly associated with longer survival (p less than 0.0001). Age and serum IgG antibody levels to cytomegalovirus did not appear to correlate. These results suggest that there are different subgroups of patients with AIDS-associated Kaposi's sarcoma, and that the initial site of disease, as well as immunologic parameters, may be useful in prognosis.

Characterization of the mononuclear infiltrate in basal cell carcinoma: a predominantly T cell-mediated immune response with minor participation of Leu-7+ (natural killer) cells and Leu-14+ (B) cells

We investigated the peritumoral inflammatory infiltrate in 22 basal cell carcinoma (BCC) from 18 patients using a series of monoclonal antibodies. In all the 22 BCC the infiltrate consisted mainly of T cells (55 +/- 15%) and only in three cases an invasion of the tumor nests by these cells was observed. The T helper (TH) subset predominated over the T suppressor/cytotoxic (TS/C) subset (TH/TS/C ratio of 1.9 +/- 0.8). In 8 of 22 BCC mild infiltrate was observed with 48 +/- 13% T cells and a TH/TS/C ratio of 1.5 +/- 0.6. In 14 of 22 BCC moderate to heavy infiltrate with 59 +/- 15% T cells and a TH/TS/C ratio of 2.0 +/- 1.0 was observed. There was a significant difference in the percentage of T cells in BCC with moderate to heavy infiltrate and that in BCC with mild infiltration. The mean percentage of HLA-DR+ cells was 54 +/- 11%; Langerhans cells (LC) 4 +/- 5%; and Leu-M5+ (monocytes and macrophages) 16 +/- 11%. Less than 2% Leu-14+(B) cells were seen in the infiltrate. The mean percentage of Leu-7+ (natural killer) cells was 4 +/- 4%, and only 1 of 22 BCC Leu-7+ cells invaded tumor nests, contacting with tumor cells. From these results we concluded that T cells play a major role in the defence against BCC proliferation. The main role of Langerhans cells and Leu-M5+ cells may be that of antigen presentation. B cells and NK cells probably play a minor role in the local defence against BCC proliferation.

Basal cell carcinoma: response to systemic chemotherapy for lung carcinoma

Two patients had regression of basal cell carcinoma while receiving systemic chemotherapy for carcinoma of the lung. The chemotherapeutic agents with some efficacy in basal cell carcinoma are reviewed. Based on our patients and data from the literature, cisplatin appears to be a drug of potential usefulness in some patients with this neoplasm.

Increased number of circulating suppressor T-lymphocytes in sun-induced multiple skin cancers

The distribution of peripheral lymphocyte subsets was studied in fifteen patients with multiple nonmelanoma skin cancers, selected according to history of ultraviolet (UV) or X-ray exposure. The skin cancer was associated with previous heavy exposure to UV light in seven patients, and past exposure to x-rays in eight patients. In the UV group, the helper T-lymphocytes/suppressor T-lymphocytes (Th/Ts) ratio was abnormally low (P less than 0.01) compared with the ratios of the x-ray and control groups. The low Th/Ts ratio was associated with an absolute increase in the number of Ts. This suggests that heavy sun exposure may cause a permanent increase in the number of Ts in certain persons. These extra T-lymphocytes may in turn prevent immune rejection of transformed keratinocytes.

Carbon dioxide laser vaporization and curettage in the treatment of large or multiple superficial basal cell carcinomas

Many of the standard forms of therapy for large or multiple superficial basal cell carcinomas are limited by significant postoperative pain, excessive scarring, and prolonged wound healing time. Combining traditional curettage with carbon dioxide laser vaporization creates a procedure that allows excellent visualization, due to the bloodless surgical field produced by the laser, minimal nonspecific thermal damage, rapid healing, and diminished postoperative pain. In addition, the speed and ease with which this procedure can be performed allow successful treatment of many lesions in a single outpatient session. We wish to report our results using this technique for the treatment of 52 patients with 370 superficial basal cell carcinomas.

Basal cell carcinoma and collagenase

The interaction of connective tissue stroma and epithelial cutaneous cancer is an active area of investigation in dermatology. Studies summarized here explore the role of collagenase in basal cell carcinoma (BCC) invasiveness. Evidence is presented to support the role of a cytokine or cytokines secreted by BCCs that stimulate collagenase production by surrounding stromal fibroblasts. Prospects for further research in this area are proposed.

Cranial invasion by basal cell carcinoma

The direct spread of basal cell carcinoma (BCC) into the bones of the cranium takes a long period. In its early stages, it may not be detectable by radiography or computerized tomography, but can be visible as pitting during surgery. Invasion through the thickness of the calvarium due to extension of a BCC of the scalp, or involvement of the cribriform plate by spread from an intranasal lesion, is serious. Examples of cranial invasion by BCC are presented. The methods used in diagnosis and treatment are outlined.

Proliferating cells of human basal cell carcinoma are located on the periphery of tumor nodules

Study of the growth characteristics of basal cell carcinoma (BCC), a relatively well-organized, slow-growing skin cancer, has been limited because of the lack of methods for propagation of the tumor off the human host. We have used newly developed techniques for transplantation and propagation of BCC on athymic mice to study [3H]thymidine incorporation by nodular BCC. In human BCCs labeled in vitro immediately after removal from the mice and in vivo on the mice, [3H]thymidine during a 4-h pulse was incorporated primarily by cells on the periphery of tumor nodules (labeling indices 6-24%) rather than by the cells more central in tumor nodules (labeling indices 0-2%). Similar results were also seen when samples of tumor freshly removed from patients were labeled in vitro. We conclude that the dividing cells within nodular BCC are primarily the cells at the edges of tumor nodules and that this characteristic is related to the slow, progressive, invasive growth of BCC.

The immunobiology of basal cell carcinoma: an in situ monoclonal antibody study

A semi-quantitative, immunoperoxidase monoclonal antibody technique was used to study the mononuclear cells surrounding 32 basal cell carcinoma specimens from 30 patients. Tumours were analysed in subgroups based on recurrence, size and ulceration. T cell counts were high (greater than 3 out of 4) for all groups while T helper/inducer and T suppressor/cytotoxic cell counts were equal (approx. 2). Macrophage counts were low for all groups, about I X 2, while B cell and Ia positive cell counts were high (greater than 3). T/B cell and T helper/suppressor cell ratios approached one for the tumours as a whole as well as the sub-groups. The relative importance and contribution of cell mediated vs. humoral immunity in keeping basal cell carcinomas in check is discussed.

Lectin-binding abnormalities in the stromal and epithelial components of basal cell carcinoma

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Human leukocyte antigen associations in basal cell carcinoma

Basal cell carcinoma is the most common form of skin cancer and is one in which both host and environmental factors are thought to play a role in its pathogenesis. For an investigation of the role of human leukocyte antigen (HLA)-associated variations in genetic susceptibility, thirty-one patients with multiple basal cell carcinomas were typed for HLA-A, B, C, and DR antigens. Patients were compared with both local and appropriate ethnic group controls. No statistically significant association with HLA-A, B, or C antigens was noted in any group. However, a significant increase in HLA-DR1 was noted in non-Irish, non-Ashkenazi patients. A tendency toward a decrease in HLA-DR3 was also noted among patients of Irish or Ashkenazi Jewish descent. The role of HLA-associated genetic factors in this form of skin cancer needs further investigation.

Meningeal carcinomatosis due to basal cell carcinoma

A case of meningeal carcinomatosis due to metastasizing basal cell carcinoma is reported. The patient was a 34-year-old woman who had a recurrent basal cell carcinoma of the upper eyelid with deep invasion. In spite of extensive surgery and radiotherapy, multiple bone metastases developed, and the patient eventually died of meningeal carcinomatosis. The possible pathogenic mechanisms of meningeal the present case, cancer cells reached the leptomeninges from adjacent vertebral metastases. It is suggested that the possibility of meningeal carcinomatosis should be considered in every patient with cancer and multiple vertebral metastases, particularly when neurologic signs involving the brain, cranial nerves, or spinal nerves are present.