Proto-oncogene c-kit expression in malignant melanoma: protein loss with tumor progression

The c-kit gene encodes a transmembrane receptor that has tyrosine kinase activity. c-kit plays a role in hematopoiesis, gametogenesis, and melanogenesis. c-kit is found in melanocytes, and there is evidence that expression is lost in melanoma. We studied 85 melanocytic lesions for c-kit by immunohistochemical techniques using a monoclonal antibody. The lesions included banal nevi, junctional and compound nevi with melanocytic dysplasia, nontumorigenic radial growth phase melanoma, tumorigenic vertical growth phase melanoma, and metastatic melanoma. We found intense membrane staining in normal melanocytes and mast cells. Staining in compound nevi was strongest in junctional and superficial dermal components, whereas dermal nevi showed weak reactivity. Dysplastic nevi stained strongly, particularly in junctional cells. In melanoma, strong reactivity was most prominent in radial growth phase disease, but there was little or no staining in vertical growth phase and metastatic melanomas. In summary, c-kit protein is expressed in normal melanocytes, benign nevi, dysplastic nevi and nontumorigenic melanoma, but expression is lost in tumorigenic primary melanomas and metastases. The role of c-kit loss in advanced melanoma requires additional investigation.     

Sustained internal sphincter hypertonia in patients with chronic anal fissure

Tenascin is a large extracellular matrix glycoprotein which is widely distributed in normal, hyperplastic and neoplastic tissues. Its function is unknown but it has been associated with the epithelial-stromal interactions, such as cell adhesion and movement which take place, e.g. in morphogenesis, cellular proliferation and neoplasia. In this study, we investigated tenascin expression in 70 benign, dysplastic and malignant melanocytic tumors by using immunohistochemistry and monoclonal anti-tenascin 143DB7C8 antibody on paraffin sections. In all types of benign nevi, both intradermal, compound and junctional, there was a moderate expression of tenascin at the dermoepidermal junction and in the papillary dermis. In dysplastic nevi, the fibrotic areas in the papillary dermis also showed a moderate staining for tenascin. Invasive malignant melanomas showed the strongest expression of tenascin. In addition to the staining at the dermo-epidermal junction and in the papillary dermis, there was a variable expression of tenascin in the reticular dermis. Intracytoplasmic tenascin was detected both in primary melanomas and melanoma metastases. In conclusion, we have shown that tenascin expression is moderately increased in benign and dysplastic melanocytic tumors and greatly increased in malignant melanomas and melanoma metastases. The function of tenascin may be related to the cellular-stromal interactions and it is possibly associated with the proliferation and spread of the melanocytic tumors.     

In situ distribution of integrin alpha 2 beta 1 and alpha-actinin in melanocytic proliferations

Integrin alpha 2 beta 1 is a transmembrane protein receptor for collagen and laminin previously reported as a melanoma tumor progression antigen. alpha-Actinin is an actin-binding protein reported to interact with the cytoplasmic domain of the beta 1-integrin chain of alpha 2 beta 1. In vitro, both alpha 2 beta 1 and alpha-actinin play a role in melanoma cell motility. In turn, increased melanoma cell line motility (measured as mean migration rates), correlates with metastasis. To determine the in situ distribution of these proteins, we used monoclonal antibodies directed against the alpha 2-integrin subunit of alpha 2 beta 1 and alpha-actinin on frozen sections of 33 melanocytic proliferations, which included dermal nevi, primary melanomas, and metastatic melanomas. We found that the superficial portion of all of the melanocytic proliferations tested stained for alpha-actinin. In benign nevi and superficial spreading melanoma, there was a notable loss of staining for alpha-actinin in the cells in the deep reticular dermis. In contrast, alpha-actinin was present on almost all of the tumor cells in the nodular melanomas and the melanoma metastases. Tumors stained either uniformly positive or uniformly negative for alpha 2 beta 1; the expression of this protein correlated with the later stages of melanoma progression. Our findings suggest that alpha-actinin protein levels initially decrease and then increase during melanocytic tumor progression, whereas the alpha 2 subunit protein appears in the later stages of melanoma progression. The variable distribution of these proteins is evidence for the differential adhesive and motile properties of subpopulations of cells in melanocytic proliferations.     

The ABCD rule in dermatoscopy: analysis of 500 melanocytic lesions

500 melanocytic lesions were examined by dermatoscopy using the ABCD rule prior to excision and histologic diagnosis. Regular nevi (n = 272) exhibited a score of 3.55 +/- 0.87, nevi with histologic signs of dysplasia (n = 190) a score of 4.0 +/- 0.68 and melanomas (n = 30) a score of 5.08 +/- 1.24. This study suggests that the ABCD rule of dermatoscopy greatly facilitates the evaluation of melanocytic lesions. When the dermatoscopic score is higher than 4.2, melanoma should be considered.     

Variants of melanoma

The current classification of malignant melanomas gives recognition to superficial spreading melanoma, lentigo maligna melanoma, acral lentiginous melanoma, and nodular types. In addition, neurotropic and desmoplastic types are recognized. The relativity inherent in the diagnosis of melanoma, provides the basis for the classification of melanomas on the basis of size. Lesions measuring 1 mm or less in vertical dimensions are unlikely to metastasize; they qualify as borderline melanocytic neoplasia of indeterminant malignant potential. The current classification has little relevancy to the category of variant nevi with the exceptions of malignant cellular blue nevus and melanoma arising in giant congenital nevi. A classification of variant melanomas as related to variant nevi is proposed. From a different perspective, a classification of melanomas with attention to nesting and cytological patterns in vertical growth is proposed: this alternate approach gives recognition to lesions that might otherwise be classified as "nevoid" melanomas. It also provides a default category for lesions that might otherwise be assigned to the Spitz nevus-like category. All of these tools for the manipulation of the real and virtual images of melanomas have been emphasized in the concept of minimal deviation melanoma.     

Melanocytic nevi and risk of cutaneous malignant melanoma in southern Spain

The main objective of this study was to assess whether cutaneous malignant melanoma (CMM) shows a stronger relation with the melanocytic nevi count at the site where CMM was diagnosed than with the melanocytic nevi count at other sites, stratifying by histologic CMM type, in a southern Mediterranean population. Cases and controls were selected from a population in southern Spain in 1988-1993. The study population included 116 incident cases with non-familial CMM (International Classification of Diseases 9th Revision (ICD-9) code 172), and 116 controls matched 1:1 for sex and age (+/- 4 years). Data were collected by personal interview, and melanocytic nevi were counted over the entire body surface by clinical skin examination performed by a dermatologist. Crude and multiple risk factor-adjusted odds ratios and 95% confidence intervals were computed by conditional logistic regression analysis. After adjustment by skin type, unexposed skin color, and sun exposure, CMM was found to occur significantly more frequently in individuals with a high number of melanocytic nevi at the same site where CMM originated (odds ratio (OR) for >8 nevi = 12.0, 95% confidence interval (CI) 1.3-108.2). The ability to predict the number of melanocytic nevi on different anatomic sites on CMM, but excluding the CMM cases on each corresponding site, was also examined. A significant trend with the number of nevi on the anterior surface of thighs was found (OR for >4 nevi = 4.5, 95% CI 1.4-14.9). Melanocytic nevi count on the melanoma site was the variable most closely related to superficial spreading melanoma subtype (SSM) (OR for >8 nevi = 82.19, 95% CI 2.72-2,454). On the other hand, the number of melanocytic nevi on the melanoma site was unrelated to risk of CMM subtypes other than SSM. These results support the hypothesis that nevi are an important risk factor for melanoma, especially SSM, in populations with a darker ethnic background.     

Melanoma mimicking dermal and Spitz's nevus ("nevoid" melanoma)

We describe two examples of malignant melanoma that present with clinical and histopathologic characteristics resembling the benign acquired dermal nevus and the spindle and epithelioid cell nevus (Spitz's nevus), respectively. Both lesions were present on the trunk of adult patients. The clinical impression in both cases was dermal nevus. Histopathologically, these lesions were fairly well circumscribed and symmetrical; they exhibited an expansile dermal proliferation of atypical nevomelanocytes in nests and fascicles with only minimal intraepidermal involvement. These lesions which we will designate as "nevoid" melanoma can be misinterpreted as benign nevi because of the absence of prominent intraepidermal pagetoid spread and the pattern of apparent dermal maturation at the base of the tumor associated with a gradual diminution of cell size. These features mimic the maturation phenomena in banal dermal nevi and spindle and epithelioid cell nevi. The differential diagnosis includes other types of melanoma, and various benign entities characterized by a predominantly dermal proliferative process, such as deep penetrating nevus and cellular neurothekeoma. The recognition of nevoid melanoma is critical so that patients with these lesions receive appropriate therapy for malignant melanoma.     

Diagnosing and treating congenital melanocytic nevus simulating malignant melanoma

Many cases reported as malignant melanomas arising in benign congenital melanocytic nevi in the neonatal period have not shown evidence of metastases after several years of follow-up. These lesions were probably pathologically misdiagnosed, thus creating a controversy regarding the precise incidence. This article describes the case of an infant with a giant melanocytic nevus simulating malignant melanoma to illustrate the proper criteria for diagnosis of this condition so extensive and unnecessary therapy procedures can be avoided.     

Nucleolar organizer regions in conjunctival nevi and melanomata

The objective of this study was to compare the argyrophil nucleolar organizer region (Ag-NOR) counts of conjunctival nevi and melanomata and to compare the efficacy of this method in their differential diagnosis. Nine histologically diagnosed conjunctival nevi and three conjunctival malignant melanomas were studied. Representative sections were stained using the AgNOR technique. Fifty cells of each melanocytic lesion were randomly selected without knowing their histologic diagnosis. The AgNORs were visualized at a magnification of x1000. They consisted of clusters >1 micron in diameter and of satellites <1 micron in diameter, which were counted and recorded for each cell separately. The mean AgNOR count for the nevi was 1.12 clusters and 1.72 satellites per cell, while the count for the melanomas was 1.6 clusters and 6.8 satellites per cell. These results are statistically significant. There was no overlap between the number of AgNOR clusters and satellites in conjunctival nevi and melanomas, indicating that the AgNOR count might be a useful tool in distinguishing benign from malignant conjunctival melanocytic lesions.     

Prognostic significance of allelic losses in primary melanoma

Loss of genetic material, including loss of loci on chromosome arms 6q, 9p, and 10q, occurs frequently in cutaneous melanoma but infrequently in benign melanocytic nevi or other melanocytic lesions, suggesting that these genetic alterations are important in the development and progression of melanoma. To examine whether allelic loss is of prognostic importance in melanoma, disease-free survival was related to loss of heterozygosity on 6q, 9p and 10q in 83 individuals with sporadic primary cutaneous melanoma. Loss of chromosome arms 6q and 10q were each significantly associated with a poorer clinical outcome (P=0.013 and P=0.001 respectively). In a subgroup of 41 subjects whose primary tumours were allelotyped, the fractional allelic loss (FAL) at 39 autosomal arms also significantly correlated with disease-free survival (P=0.013), with an increase in FAL associated with a poorer outcome; this association remained significant when controlled for tumour thickness (P=0.035). In addition, a greater proportion of cells were immunopositive for Ki67 antigen, p53 and p21WAF1 protein in the primary melanomas than in the benign melanocytic nevi, however, only p53 over-expression was significantly associated with improved survival (P=0.041).     

'Tubular' epithelioid cell nevus: a new variant of Spitz's nevus

The term Spitz's nevus refers to a large spectrum of nevi composed of spindle and/or epithelioid cells. We report on a hitherto undescribed tubular variant of a dermal epithelioid nevus, characterized by aggregates composed exclusively of cuboidal cells with the prominent feature of tubular or microcystic structures. Immunohistochemically, the epithelioid cells expressed melanocytic markers (S-100, NKI/C3) lacking markers for cytokeratin or carcinoembryonic antigen. The three-dimensional analysis of the lesions by confocal laser scanning microscopy revealed the structural configuration of tubular or microcystic empty spaces bordered by cuboidal nevus cells. This rare variant of epithelioid nevus is another example for the remarkable diversity of Spitz's nevi.     

Effect of Pichia anomala killer toxin on Candida albicans

BACKGROUND: An acral lentiginous melanoma in situ on the sole is often difficult to differentiate with the naked eye from an acquired plantar melanocytic nevus. Recent technical advances in epiluminescence microscopy have contributed to the differentiation of these two pigmented skin lesions. OBJECTIVE: In this study, the correlation between dermatoscopic and histopathologic findings of acral lentiginous melanoma in situ on the sole are compared to those of acquired plantar melanocytic nevi. METHODS: Three acral lentiginous melanomas in situ on the sole, and two cases of acral lentiginous melanoma were compared with 50 acquired plantar melanocytic nevi by means of dermatoscopy and histopathology. Results: The dermatoscopic surface profiles of acquired melanocytic nevi were composed of linear pigmentation accentuated mainly on the sulcus superficialis. Histologically, some areas of the sulcus superficialis corresponded to rete ridges of the epidermis, and nests of nevus cells were also often located there. In contrast, the acral lentiginous melanomas in situ showed diffuse, irregularly shaped pigmentation distributed in a disorderly fashion over the entire surface. Histologically, isolated areas of proliferation and small nest formations of atypical melanocytes were irregularly distributed in the epidermis. CONCLUSION: A distinctive dermatoscopic feature of acral lentiginous melanoma in situ is diffuse and irregular pigmentation over the entire surface of the lesion. This feature is helpful for differentiating acral lentiginous melanoma in situ from acquired plantar melanocytic nevi.     

Nursing staff perceptions of the use and reduction in the use of physical restraints

Substance P (SP) is a neuropeptide found in both the central and peripheral nervous system. In the skin, SP-containing neurons stimulate the release of histamine from connective tissue mast cells (MC). SP also can potentiate neoangiogenesis and induce dermal fibrosis. MC-derived histamine has potent vasoactive effects, is angiogenic, and promotes tissue fibroplasia. In addition to histamine, MC contain many other angiogenic factors and a variety of cytokines, growth factors, and proteolytic enzymes implicated in tissue remodeling, and normal as well as tumor-associated neoangiogenesis. Many MC-derived factors, including histamine, can enhance melanoma cell growth directly. MC often concentrate around cutaneous melanomas which also frequently are associated with angiogenesis and peritumoral fibrosis. The precise mediators of these responses have not been well defined. We evaluated by immunohistochemistry cutaneous lesions representing stages of progression of malignant melanoma and its precursor lesions for the expression of SP. SP was expressed in 17/25 (68%) primary invasive malignant melanomas, 2/5 (40%) metastatic melanomas, 6/10 (60%) melanomas in situ, 7/12 (58%) atypical (dysplastic) nevi, and 4/10 (40%) spindle and epithelioid cell (Spitz) nevi, but was not detected in any (0/11, 0%) acquired benign melanocytic nevi (p<0.05). Invasive melanomas were immunolabeled in both the intraepidermal and the dermal components of the lesions. For those atypical and Spitz nevi which expressed SP, most of the immunoreactive melanocytes were located at the dermal-epidermal junction overlying areas of papillary dermal fibrosis. The results show differential expression of SP among cutaneous melanocytic lesions and suggest that the expression of this neuropeptide together with other factors may contribute to some of the host responses associated with these lesions.     

Heterogeneous expression of immunotherapy candidate proteins gp100, MART-1, and tyrosinase in human melanoma cell lines and in human melanocytic lesions

In recent years, it has become evident that T cells can recognize peptides of melanocytic lineage antigens such as gp100, MART-1, and tyrosinase at the tumor cell surface and can subsequently destroy these cells. It is thus feasible to develop immunotherapeutic approaches based on the melanocytic marker profiles of melanoma cells. One of the predictors of the success rate of such a treatment is the extent of positive (target) tumor cells within the lesions of the patient. First, we investigated the presence of these three proteins in 18 human melanoma cell lines using RT-PCR and immunohistochemistry. In 11 cell lines, mRNA and protein of all three markers could be detected; in one cell line, only two markers were present, and six melanoma cell lines showed no evidence for these markers. Secondly, we stained frozen sections of 105 human melanocytic lesions, 13 common nevocellular nevi, 13 atypical nevi, 13 early primary melanomas (Breslow < 1.5 mm), 25 advanced primary melanomas (aPM; Breslow > or =1.5 mm), and 41 melanoma metastases (MM) with antibodies against glycoprotein 100, melanoma antigen recognized by T cells, and tyrosinase. In addition, we used the 3,4-dihydroxy-L-phenylalanine reaction to detect tyrosinase enzyme activity as a confirmation of the tyrosinase immunohistochemical results in a subset of the lesions. In the benign lesions, glycoprotein 100 was more prominently expressed in epidermal melanocytes, whereas melanoma antigen recognized by T cells was encountered in all or nearly all dermal melanocytes in all nevocellular nevi and atypical nevus lesions. Tyrosinase was found in a lower percentage of melanocytes, both in the epidermis and in the dermis within these lesions. With regard to heterogeneity of staining within the malignant lesions, we found that 54% (early primary melanomas), 48% (aPMs), and 56% (MM) of the lesions stained within the same staining category for all three proteins studied. Approximately 17% of the aPM and MM lesions did not show positive tumor cells for any of the three proteins. We conclude that a subgroup of patients with high expression should be selected for immunotherapeutic treatment approaches based on the presence of these proteins.     

Associated factors in the prevalence of more than 50 common melanocytic nevi, atypical melanocytic nevi, and actinic lentigines: multicenter case-control study of the Central Malignant Melanoma Registry of the German Dermatological Society

Several case-control studies identified common and atypical melanocytic nevi as major risk indicators for the development of cutaneous melanoma. The present investigation was planned to detect factors associated with the prevalence of these melanoma risk markers. Whole-body examination findings and interview data of 513 melanoma patients and 498 age- and sex-matched control subjects were analyzed. Existence of more than 50 common melanocytic nevi and the presence of atypical melanocytic nevi were significantly related to age and gender, with significantly elevated relative risk for their prevalence before the age of 60 and in males. Additionally, sunburns before the age of 20 were significantly associated with both more than 50 common melanocytic nevi (relative risk = 1.7) and the presence of atypical melanocytic nevi (relative risk = 1.5). Actinic lentigines were found more frequently with increasing age, and the presence of actinic lentigines was significantly related to a tendency of freckling in adolescence (relative risk = 2.0) and to two or more sunburns after the age of 20 (relative risk = 1.6). In conclusion, sunburns before the age of 20 contribute to the development of multiple melanocytic nevi and atypical melanocytic nevi. In adulthood, this type of sun exposure is associated with the development of actinic lentigines. The relative risk of developing cutaneous melanoma increases in association with the development of these benign melanocytic lesions.     

Adhesion molecule expression in normal skin and melanocytic lesions. Role of UV-irradiation and architectural characteristics in nevi

Cell adhesion between surfaces of cells and to extracellular matrices represents a fundamental mechanism in tissue organization and influences the biological behaviour and the architecture of tumors. We investigated the expression of various adhesion molecules in normal skin (n=5), nevi (n=29), and malignant melanoma (n=10) by immunohistochemistry. Special attention was paid to the correlation between adhesion molecule expression and the respective architectural features, e.g. UV-induced morphological changes, and the arrangement of melanocytes in congenital nevi. In nevi, a single erythemagenic dose of UV-light did not influence the integrin expression of melanocytes, but results in an upregulation of alpha3 beta1- and alpha6 beta1-integrin within the suprabasal layers of the epidermis. This suprabasal labelling was associated with an increased number of suprabasal melanocytes in UV-irradiated nevi which were detected with HMB-45 antibody. Nine of 10 congenital nevi demonstrated a labelling of alpha4 beta1-integrin only in melanocytes of the deeper dermis. This integrin previously has been associated with high tumor thickness and the clinical outcome in melanomas. The integrin profile observed in melanomas differed in part from that seen in nevi with expression of beta2- and beta3-integrins in some cases. The results may indicate a correlation between adhesion molecule expression and histopathological findings in melanocytic lesions.     

Pluripotential melanoblastoma, a unifying concept on malignancies arising in congenital melanocytic nevi: report of two cases

Congenital melanocytic nevi are benign lesions present at birth and considered to be caused by a maldevelopment of the neural crest. The malignant potential of the congenital melanocytic nevi have been extensively addressed by several authors, and malignant melanoma is the most frequent neoplasm arising in these lesions. The present report describes two patients with congenital melanocytic nevi in which malignant melanoma with undifferentiated areas showing rhabdomyoblastic differentiation developed. The findings suggest that these mixed neoplasms may be recapitulating the differentiation potential of the ectomesenchyme-neural crest cells. We advocate the term "melanoblastoma" when referring to them.     

Dynamics of cell-associated viremia and antibody response during the early phase of lentivirus infection in sheep

OBJECTIVE: To investigate the characteristic epiluminescent microscopic features of early lesions of malignant melanoma affecting glabrous skin, which is the most prevalent site of the neoplasm in nonwhite populations. DESIGN: The epiluminescent microscopic features of various kinds of melanocytic lesions affecting glabrous skin were investigated using a videomicroscope. All the diagnoses were determined clinically and histopathologically using the standard criteria. SETTING: A dermatology clinic at a university hospital. PATIENTS: The following 130 melanocytic lesions consecutively diagnosed at our department were examined: 16 lesions of acral lentiginous melanoma, 6 lesions of malignant melanoma in situ, and 108 lesions of benign melanocytic nevus (acquired or congenital). MAIN OUTCOME MEASURE: The incidence of each characteristic epiluminescent feature was compared among disease categories. RESULTS: On epiluminescent microscopy, malignant melanoma in situ and the macular portions of invasive malignant melanoma showed accentuated pigmentation on the ridges of the skin markings, which are arranged in parallel patterns on glabrous skin. This "parallel ridge pattern" was found in 5 (83%) of 6 lesions of malignant melanoma in situ and in 15 (94%) of 16 lesions of malignant melanoma. The parallel ridge pattern was rarely found in the lesions of benign melanocytic nevus. Most benign melanocytic nevi showed 1 of the following 3 typical epiluminescent patterns: (1) a parallel furrow pattern exhibiting pigmentation on the parallel sulci of [he skin markings (54%), (2) a latticelike pattern (21%), and (3) a fibrillar pattern showing filamentous or meshlike pigmentation (15%). The remaining 11 benign nevi (10%) showed a nontypical pattern. CONCLUSION: Because epiluminescent microscopic features of early malignant melanoma on glabrous skin are characteristic, we can effectively detect early lesions using this noninvasive method.     

Protein expression of the cell-cycle inhibitor p27Kip1 in malignant melanoma: inverse correlation with disease-free survival

In the present study we analyzed, by immunohistochemistry, a panel of human melanomas for protein expression of the cyclin-dependent kinase (cdk) inhibitor p27Kip1 and evaluated whether deregulated expression correlates with clinical outcome for this type of cancer. We found that p27Kip1 was strongly expressed by normal melanocytes and benign nevi, whereas in malignant melanoma, a heterogeneous expression pattern was observed. In the case of nodular melanomas, the level of p27Kip1 was found to correlate significantly with the thickness of the tumor, with less protein expressed in thicker lesions. We also found that patients having tumors with fewer than 5% p27Kip1-staining cells had a significantly higher risk of early relapse of their disease compared with those expressing moderate or high levels. In contrast, the level of p27Kip1 did not correlate with tumor thickness or disease-free survival in patients with superficial spreading melanomas, suggesting that p27Kip1 may play different roles in these two major pathological subgroups of malignant melanoma. Furthermore, p27Kip1 did not appear to have an influence on overall survival for either subgroup. When we examined the combined effect of p21WAF1/CIP1 (another cdk inhibitor) and p27Kip1 on clinical outcome, we found that analysis of these two cdk inhibitors together may have greater prognostic potential than either alone. In conclusion, our results suggest that virtually complete loss of p27Kip1 protein expression has potential importance as a prognostic indicator of early relapse in patients with nodular melanoma The results, furthermore, underscore the value of analyzing multiple cell cycle regulatory proteins to obtain the most reliable indication of prognosis.