Staining of melanocytic neoplasms by melanoma antigen recognized by T cells

We stained benign melanocytic nevi and malignant melanoma with antibodies to melanoma antigen recognized by T cells (Mart-1) to determine if this was useful in differentiating benign from malignant melanocytic neoplasms. Forty-five primary malignant melanomas and 71 benign melanocytic nevi were stained with antibodies to Mart-1. Two cases of malignant melanoma metastatic to lymph node and three cutaneous metastases of malignant melanoma were also stained. The degree of staining was graded into diffuse positive staining, focal positive staining, and negative staining. Thirty-six of 45 primary malignant melanomas stained diffusely positive with antibodies to Mart-1. This included three of five desmoplastic malignant melanomas that showed positive staining. Four melanomas showed faint or focal positive staining. One of two metastases to lymph node showed strong positive staining and one showed no staining. All three cutaneous metastases showed diffuse positive staining. Sixty-one of 71 melanocytic nevi showed no staining or faint staining with antibodies to Mart-1. Ten of 71 melanocytic nevi showed strong positive staining. The majority of these were congenital nevi. Staining with antibodies to Mart-1 antigen was a useful marker of malignant melanoma. However, staining may also be seen in benign melanocytic neoplasms. The presence or absence of staining for Mart-1 antigen cannot be used to differentiate benign melanocytic nevi from malignant melanocytic tumors.     

Phosphoinositide 3-kinase is not overexpressed in melanocytic lesions

BACKGROUND: Although various studies have stressed the role of phosphatase and tensin homologue deleted on chromosome 10 (PTEN)-PI3K-AKT pathway in the progression of melanocytic lesions, little is known about the expression pattern of PI3K in these lesions. OBJECTIVE: To investigate the expression pattern of PI3K in benign and dysplastic nevi, primary melanomas, and metastatic melanomas and the role of PTEN and PI3K in melanocytic tumor progression. METHODS: Tissue microarrays were constructed using formalin-fixed, paraffin-embedded archival tissue blocks from 89 melanocytic lesions: 17 benign nevi, 18 dysplastic nevi, 23 primary melanomas, and 31 metastatic melanomas. Expression of PTEN and PI3K (p85 and p110 subunits) was evaluated immunohistochemically, and the number of cells and labeling intensity were assessed semiquantitatively. RESULTS: Both benign and dysplastic nevi showed strong cytoplasmic staining with PTEN, which was subsequently less in melanomas and completely lost in the metastatic lesions. Eleven of 17 (64%) benign nevi, seven of 10 (70%) dysplastic nevi, four of 23 (17%) primaries, and one of 31 (3%) visceral or lymph node metastasis showed strong positivity. Loss of PTEN expression from benign and dysplastic nevi to melanoma was statistically significant (p=0.001). Although few cells showed reactivity for phosphoinositide 3-kinase (PI3 kinase)-p85 subunit, strong positivity was not detected in the cytoplasm of benign, malignant, or metastatic lesions, except for a single visceral metastasis. Three of 13 (23%) nevi showed positivity for the p110 subunit. No positivity was observed in the dysplastic nevi. Two of 22 (9%) melanomas, one of 14 (7%) visceral metastasis, and three of 12 (25%) lymph node metastasis showed strong positivity. There was no statistical difference in PI3 kinase expression in benign and malignant melanocytic lesions (p=0.2). CONCLUSION: PI3K is not overexpressed in melanocytic lesions.     

Comparison of pHH3, Ki-67, and survivin immunoreactivity in benign and malignant melanocytic lesions

Differentiating malignant melanoma from benign melanocytic lesions can be challenging. We undertook this study to evaluate the use of the immunohistochemical mitosis marker phospho-Histone H3 (pHH3) and the proliferation markers Ki-67 and survivin in separating malignant melanoma from benign nevi. Sixty-six melanocytic lesions (18 malignant melanomas, 8 Spitz nevi, 20 dysplastic nevi, and 20 compound nevi) were stained with antibodies to pHH3, Ki-67, and survivin. No pHH3 expression was detected in the dermis of compound and dysplastic nevi. Rare mitoses were observed in the superficial dermis in 3 of 8 Spitz nevi (37%). Staining for pHH3 was higher in malignant melanomas [average 25 per 10 high-power field (HPF), range 2-75 per 10 HPF] than in Spitz nevi (average 0.5 per 10 HPF, range 0-2 per 10 HPF) and was heterogeneously distributed in the malignant melanomas compared with a superficial dermal location in Spitz nevi. There was no cytoplasmic staining for survivin in any of the 66 melanocytic lesions and no nuclear staining in any of the benign ones. Survivin nuclear staining was present in 12 of 18 cases of malignant melanoma (67%) with an average index of 7% (range 0%-15%). In benign melanocytic lesions, the Ki-67 index was less than 5% (range 0%-4%) and staining was present close to the dermo-epidermal junction compared with an average index of 27% in melanomas (range 5%-50%) and a generally heterogeneous pattern of staining throughout the dermis. pHH3 and Ki-67 can be useful adjuncts to histopathology to separate malignant melanoma from benign nevi. pHH3 is especially useful to highlight mitoses and to rapidly assess the mitotic activity in melanocytic lesions.     

Cutaneous Rhizopus in an Immunosuppressed Patient

Background: Progression through the cell cycle is controlled by cyclins, cyclin‐dependent kinases and cyclin‐dependent kinase‐inhibitory proteins. The role of cyclin D1 in the development, progression and prognosis of melanomas is controversial. The goal of this study is to evaluate the role of cyclin D1 in benign and malignant melanocytic lesions of the skin. Methods: A total of 101 melanocytic lesions of the skin including compound nevi (21), intradermal nevi (18), melanoma in situ (3), primary invasive melanoma (30), and metastatic melanoma (29) were evaluated for cyclin D1 overexpression by immunohistochemistry. The following tiered system was used for scoring: 0% of cells with nuclear staining (score 0), 1–19% nuclear staining (score 1), 20–49% nuclear staining (score 2), and 50% or greater nuclear staining (score 3). Results: The average score for primary melanomas was significantly higher compared to nevi (p = 0.0046), and for in situ melanomas compared to primary invasive melanomas (p = 0.011). There was slightly higher level of expression in compound nevi versus intradermal nevi. Conclusion: Our study indicates that cyclin D1 expression is increased in malignant compared to benign melanocytic lesions. Further studies are needed to ascertain the biological role of cyclin D1 in melanocytic lesions of the skin.     

Nerve growth and expression of receptors for nerve growth factor in tumors of melanocyte origin.

Nerve growth factor (NGF) stimulates growth and differentiation of sensory and sympathetic neurons. It is not known what role NGF plays in melanoma development, but nevus and malignant melanoma cells express NGF-receptor (NGF-R). We counted nerve fibers within melanocytic nevi, primary cutaneous melanomas, and cutaneous melanoma metastases using a monoclonal antibody (MoAb) as marker against a 200-kD glycoprotein that is expressed on human nerves. The expression of NGF-R was studied in serial cryostat sections using a MoAb against the NGF-R. Compared to normal skin, increased numbers of nerve fibers were found in 72 melanocytic nevi. In congenital nevi their number significantly increased with age. In 47 primary cutaneous melanomas the number of nerve fibers decreased in proportion to tumor thickness. In 33 cutaneous melanoma metastases no accumulation of nerve fibers was found. NGF-R was not expressed in normal skin melanocytes and in the majority of nevus cells in melanocytic nevi. Considerable numbers of NGF-R-positive nervus cells were found only in some congenital nevi and few acquired nevi with dysplastic features. By contrast, in primary and metastatic melanomas higher expression of NGF-R was observed. The increased number of nerve fibers in melanocytic nevi suggests that neurite-promoting factors are produced in situ. Production of such factors appears to be lost in malignant melanoma cells. The finding of an inverse correlation between an abundance of nerve fibers in NGF-R-poor nevi and a high expression of NGF-R in melanomas that show no evidence of nerve growth suggest a role of NGF and its receptor in malignant melanocytic tumors.     

Immunohistochemical expression of cyclooxygenage-2 in melanocytic skin lesions

Background Several reports have shown expression of cyclooxygenase‐2 (COX‐2) in malignant skin tumors. COX‐2 has also recently been reported as a marker of malignant melanoma (MM). Objective Our aim was to investigate whether there is a difference in the immunohistochemical expression of COX‐2 between malignant and benign melanocytic lesions of the skin. Methods We selected 40 archival cases of MM including 10 cases of superficial spreading melanoma, 10 of lentigo maligna melanoma, 10 of nodular melanoma, and 10 of acral lentiginous melanoma. For comparison, we also selected 35 benign melanocytic lesions, which included 15 nonatypical nevi and 10 atypical nevi. The remaining 10 cases were Spitz nevi. COX‐2 immunohistochemical staining was performed, and intensities were assessed quantitatively. Results The MM group and the benign melanocytic nevi group showed a highly statistically significant difference in the intensity of COX‐2 expression (P < 0.0001). Staining intensity in the dermal component of MM cases also showed a tendency to increase with increasing tumor depth. By contrast, the intensity of the dermal component in the melanocytic nevi group decreased with increasing depth as the nevus cells matured from type A to type C cells. No statistical difference was noted between the MM and Spitz nevi cases (P = 0.20). Conclusions Malignant melanoma shows stronger immunohistochemical expression of COX‐2 than benign melanocytic nevi. Although COX‐2 cannot be used alone to differentiate MM from melanocytic nevi, it may serve as an aid in the differential diagnosis of melanocytic skin lesions.     

Loss of p14<Superscript>ARF</Superscript> expression in melanoma

Lack of p14ARF expression or its functional inactivation has been observed in human and murine carcinomas. Although very few mutations of p14ARF have been detected in some cancer types, changes in expression seem to play an important role in the development of other human cancers such as mesotheliomas. To examine the p14ARF gene and expression of p14ARF protein in melanomas, we screened eight human melanoma cell lines and primary human melanocytes by RT-PCR, sequencing and immunoblotting. All melanoma cell lines analyzed expressed wild-type p14ARF mRNA as well as protein. P14ARF expression was investigated by immunohistochemical staining of 32 tissue samples of benign melanocytic nevi (n=14), melanomas (n=12) and melanoma metastases (n=6). In contrast to the results obtained from cell lines in vitro the immunohistochemical stainings revealed a correlation between the progression of melanoma and the lack of the p14ARF protein expression. Positive p14ARF protein staining was observed in 11 of 14 benign nevi, in 3 of 12 melanomas and in 0 of 6 melanoma metastases. In summary, we demonstrated a significant inverse correlation between p14ARF protein expression and progression of melanocytic tumors since the amount of p14ARF protein staining decreased from benign melanocytic nevi to metastatic melanoma in situ. These results suggest that p14ARF inactivation is important in the development of melanomas.     

Benign melanocytic lesions: Risk markers or precursors of cutaneous melanoma?

Background: The role of benign melanocytic lesions as precursors and not only as risk markers for the development of cutaneous melanoma is controversial.Objective: The purpose of the study was to assess the frequency of the histologic association of benign melanocytic lesions with cutaneous melanoma of a maximum thickness of 1.00 mm. The possibility that the spatial association of benign lesions with melanoma may be co-incidental was also investigated.Methods: The study subjects representing 289 cases of cutaneous melanoma of maximum thickness 1.00 mm (or less) were examined histologically for the presence of an associated benign melanocytic lesion(s), including lentiginous melanocytic proliferation; junctional, compound, or intradermal nevus; dysplastic nevus; and congenital nevus contiguous with or adjacent to the melanoma. The effects of age, tumor thickness, level of invasion, histologic type, and anatomic site on the association of benign melanocytic lesions with melanoma were assessed. In the control subjects 40 basal cell carcinomas and 38 compound nevi (not dysplastic) randomly chosen and matched for age (±1 year) and site (head/neck, trunk, upper and lower limbs) with a melanoma case were examined to assess the proportion of these cases associated with benign lesions compared with the matched melanoma cases.Results: A nevus was associated with melanoma in 51% of cases (n = 147). Of these, 82 (56%) were dysplastic nevi, 61 (41%) were common acquired nevi, and 4 (3%) were congenital nevi. Lentiginous melanocytic proliferation was present in the epidermis adjacent to 219 melanomas (75%) and in 44% of these cases (n = 97) a coexisting nevus was also present.Conclusion: The results of this study lend further support to the concept of common acquired nevi and dysplastic nevi as precursors of cutaneous melanoma. In addition, lesions diagnosed clinically as simple lentigo and solar lentigo may be important as potential precursors of melanoma, particularly in the elderly.     

Expression of activated Akt in benign nevi, Spitz nevi and melanomas

BACKGROUND: Activated Akt expression (p-Akt) is reportedly increased in many melanomas as compared with benign nevi. The purpose of this study was to evaluate and compare p-Akt immunohistological staining in benign nevi, Spitz nevi and primary melanomas. METHODS: Immunostaining for phosphorylated Akt was performed in 41 melanocytic lesions previously classified as benign intradermal nevus (14 lesions), Spitz nevus (9 lesions) or melanoma (18 lesions). Lesions were graded for intensity of p-Akt staining by two independent observers (0, no staining; 1, slightly positive; 2, moderately positive; 3, highly positive). Scores were averaged, and statistical analyses were performed. RESULTS: Benign nevi showed less staining (mean score 1.18) compared with Spitz nevi (mean score 2.11) and melanomas (mean score 2.19). This difference was statistically significant between benign nevi and melanomas (p = 0.0047) and benign nevi and Spitz nevi (p = 0.0271). No statistical difference was detected in staining between Spitz nevi and melanomas (p = 0.8309). CONCLUSIONS: Activated Akt expression is increased in Spitz nevi and melanomas as compared with benign intradermal nevi, but is unlikely to prove useful in differentiating between the former.     

Fibroblast activation protein: differential expression and serine protease activity in reactive stromal fibroblasts of melanocytic skin tumors

Growth and metastasis of solid neoplasms require the recruitment of a supporting tumor stroma. A highly consistent trait of tumor stromal fibroblasts in most epithelial cancers is the induction of fibroblast activation protein (FAP), a member of the serine protease family. Recently it was demonstrated that FAP has both dipeptidyl peptidase and collagenolytic activity capable of degrading gelatin and type I collagen. In this study, we describe the expression and enzyme activity of FAP in benign and malignant melanocytic skin tumors. FAP-positive fibroblasts were detected immunohistochemically in the reactive stroma of all melanocytic nevi tested. In primary and metastatic melanomas an upregulation of FAP expression in the reactive mesenchyme could be observed. Whereas 30% of the nevi revealed additional FAP expression on subsets of melanocytic cells, melanoma cells from primary and metastatic melanomas were FAP negative. This may indicate a possible role for FAP in the control of tumor cell growth and proliferation during melanoma carcinogenesis. Consistent with this in vivo expression pattern FAP enzyme activity could be detected by a specific immunocapture assay in extracts of melanocytic nevi and melanoma metastases, whereas no significant activity was detectable in normal adult skin. Strong protein expression of FAP was observed in patterned structures restricted to a subset of the melanoma metastases. Our findings that these FAP-positive structures showed no overlap with endothelial cell surface markers, nor with various melanoma antigens, suggest that FAP is a marker for specific stromal-cell-derived patterns in cutaneous melanoma metastases.     

Laminin‐5 Expression in Melanocytic Lesions of the Skin

Background: Laminin‐5 is a basement membrane constituent that functions as an anchoring filament to integrin‐derived hemidesmosomes, and has been detected at the invasive front (tumor‐stromal interface) in many types of carcinomas. Our goal was to analyze laminin‐5 expression in melanocytic lesions and evaluate its role in tumor progression. Design: Immunohistochemical staining for laminin‐5 was performed on 101 cutaneous melanocytic lesions including 41 nevi, 31 primary melanomas, and 29 metastatic melanomas. A standard immunoperoxidase technique (ABC) was used with DAB chromagen and a primary monoclonal antibody to the laminin‐5 gamma2 chain (clone D4B5, 1:50, Chemicon International, Temecula, CA). Any degree of staining in melanoma cells or at the tumor‐stromal interface was considered positive. Results: Positive staining for laminin‐5 was observed in three of the primary melanomas (10.7%), three of the metastatic melanomas (10.3%), and none of the nevi. In primary melanomas, staining was observed predominately at the tumor‐stromal interface. In metastatic lesions, staining was observed around individual melanoma cells and melanoma cell nests.Conclusion: Expression of laminin‐5 was detected in a small percentage of primary and metastatic melanomas and in none of the nevi studied. Laminin‐5 expression does not appear to be essential for the development of melanomas or their metastases.     

Loss of claudin-1 expression in tumor-associated vessels correlates with acquisition of metastatic phenotype in melanocytic neoplasms

Claudins are a family of transmembrane proteins involved in cell-to-cell adhesion and are believed to be the main component of tight junctions. Recent studies have suggested that some metastatic solid tumors lack claudin expression. It is unknown whether claudins play a role in cutaneous melanoma. Immunohistochemical studies were performed on tissue microarrays containing 19 benign melanocytic nevi (BN), 21 dysplastic nevi (DN), 23 primary malignant melanomas (MMs), and 31 metastatic melanomas (MMMs) using a polyclonal anti-claudin-1 antibody. Immunoreactivity in tumor cells and associated vessels was graded by intensity and by percentage of reactive cells. Normal epidermis served as internal control (3+ labeling). Cases with at least 2+ labeling in more than 25% of the cells were considered positive. Claudin-1 expression was present in 37% of BN, 24% of DN, 26% of MM, and 3.2% of MMM. Tumor-associated vessels showed the following results: 11 of 19 (58%) in BN, 14 of 21 (67%) in DN, 17 of 23 (74%) in MM, and 6 of 31 (19%) in MMM. A significant loss of expression was noted between MMM and all other lesions in tumor cells and associated vessels. There was no significant difference between BN, DN, and MM. Within primary melanomas, there was a significant correlation between expression of claudin in tumor cells and Clark level/Breslow thickness. Also significant was a decreased expression of claudin in tumor vessels of lesions with higher Breslow thickness or Clark level. These data suggest that loss of claudin-1 may play a significant role in the acquisition of metastatic phenotype in cutaneous melanoma. Cohn ML, Goncharuk VN, Diwan AH, Zhang PS, Shen SS, Prieto VG. Loss of claudin-1 expression in tumor-associated vessels correlates with acquisition of metastatic phenotype in melanocytic neoplasms.     

Cdc7 expression in melanomas, Spitz tumors and melanocytic nevi

Background:  Cdc7 is a serine-threonine kinase required for initiation of DNA replication that may play a role in the development and progression of melanoma.
Materials and Methods:  Tissue microarrays containing 40 melanomas, 40 Spitz tumors and 30 nevi were constructed. Staining for Cdc7 was scored semiquantitatively according to intensity and extent, and the values were converted into composite scores.
Results:  Nodular melanomas, atypical Spitz tumors and superficial spreading melanomas had the highest scores (nodular melanomas, 3.67; atypical Spitz tumors, 2.78 and superficial spreading melanomas, 2.44). Typical Spitz nevi, dysplastic nevi and ordinary nevi had the lowest scores. Cdc7 expression in melanomas differed significantly from non-Spitz nevi (p < 0.001). The difference was also significant when invasive melanomas were compared with dysplastic nevi (p < 0.005) and when invasive melanomas were compared with non-atypical Spitz nevi (p < 0.001). However, there was no significant difference between invasive melanomas and atypical Spitz tumors (p = 0.69) or between dysplastic nevi and ordinary nevi (p = 0.73).
Conclusion:  Cdc7 expression differs significantly among cutaneous melanocytic neoplasms and can be evaluated by routine immunohistochemical methods. The results suggest that differences in Cdc7 expression may account for some of the differences between malignant melanomas and benign melanocytic nevi.     

CD44 and melanocytic tumors: a possible role for standard CD44 in the epidermotropic spread of melanoma

CD44 is a polymorphic family of cell membrane glycoproteins that mediate cell-matrix and cell-cell interactions involved in the mechanisms of tumor invasion and metastasis, and are subject to differential regulation during normal and malignant cell growth. We have investigated immunohistochemically the expression of CD44S and the variant isoforms CD44v3 and CD44v6 in paraffin-embedded tissue from 5 Spitz nevi, 3 compound melanocytic nevi, 2 blue nevi, 6 primary melanomas, 15 cutaneous metastases (three epidermotropic, nine dermal and three ulcerated) and 10 lymph node metastases of melanoma. Melanocytes were extensively positive for CD44S in primary melanomas and benign melanocytic proliferations. Among 15 cases of cutaneous metastases of melanoma, the three epidermotropic metastases, as well as one of the three ulcerated ones were positive for CD44S. CD44S expression was diminished or totally absent in six of the nine dermal metastases, in two of the ulcerated metastases and in seven of the ten lymph node metastases. CD44v3 and CD44v6 melanocytic expression was absent in all the lesions studied.
According to our results, selective retention of CD44S expression by melanocytes in epidermotropic metastases of melanoma seems to indicate that preservation of CD44S may contribute to the intraepidermal spread of melanoma.     

Analysis of APAF-1 expression in human cutaneous melanoma progression

APAF-1 plays a pivotal role in mitochondria-dependent apoptosis, binding to cytochrome c and favoring activation of caspase-9. It has been shown that epigenetic silencing of the APAF-1 gene is a common event in several metastatic melanoma cells in vitro. We determined, by Western blot, variation in the level of expression of APAF-1 in several human melanoma cell lines and, by immunohistochemistry, in a group of 106 histological samples including benign and malignant melanocytic lesions. We observed APAF-1 down-regulation or loss of expression in two metastatic melanoma cell lines, compared to primary melanoma cell lines. The immunohistochemical analysis revealed a significant difference in APAF-1 staining between nevi and melanomas. In addition, we found a significant negative correlation between APAF-1 expression level and tumor thickness and between primary melanomas and metastases. We conclude that loss of APAF-1 expression can be considered as an indicator of malignant transformation in melanoma.     

Genetic interaction between NRAS and BRAF mutations and PTEN/MMAC1 inactivation in melanoma

Extant evidence implicates growth factor signaling in the pathogenesis of many tumor types, including cutaneous melanoma. Recently, reciprocal activating mutations of NRAS and BRAF were found in benign melanocytic nevi and cutaneous melanomas. We had previously reported a similar epistatic relationship between activating NRAS mutations and inactivating PTEN/MMAC1 alterations. We thus hypothesized that BRAF and PTEN/MMAC1 mutations may cooperate to promote melanoma tumorigenesis. Overall, 40 of 47 (85%) melanoma cell lines and 11 of 16 (69%) uncultured melanoma metastases had mutations in NRAS, BRAF, or PTEN/MMAC1. NRAS was exclusively mutated in nine of 47 (19%) cell lines and two of 16 (13%) metastases, whereas BRAF was solely mutated in 28 of 47 (60%) cell lines and nine of 16 (56%) metastases. In the 12 of 15 melanoma cell lines (80%) and two of two melanoma metastases with PTEN alterations, BRAF was also mutated. These findings suggest the existence of possible cooperation between BRAF activation and PTEN loss in melanoma development.     

Increased tenascin expression in melanocytic tumors

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 L43DB7C8 antibody on paraffin sections. In all types of benign nevi, both intradermal, compound and functional, 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 clermis 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 clermis, there was a variable expression of tenascin in the reticular dermis. Intracyloplasmic 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.     

Expression of galanin in melanocytic tumors

IntroductionGalanin is a neuropeptide with wide-ranging effects, especially within the endocrine and nervous systems. Galanin and its receptors are present in human skin. Galanin is expressed in different neural, endocrine and neuroendocrine tumors and, on the other hand, several neuropeptides, particularly α-MSH, seem to play a role in the pathogenesis of melanoma.ObjectiveTo investigate the expression of galanin in cutaneous melanomas and melanocytic nevi and correlate it with α-MSH expression and several prognostic factors for melanoma.Material and methodsWe performed an observational and retrospective study of the immunohistochemical expression of galanin and α-MSH in samples of cutaneous melanomas diagnosed in the last 5 years in the San Jorge Hospital, Huesca (Spain). Different types of melanocytic nevi were also analyzed.ResultsA total of 130 pigmented lesions were studied: 38 primary cutaneous melanomas, 6 cutaneous melanoma metastases and 86 melanocytic nevi. Immunostaining with galanin and α-MSH was significantly higher in melanomas than in melanocytic nevi (p < 0.001), although spindle cell and blue nevi showed significant expression of α-MSH. More than 50 % of nodular melanomas and 90 % of superficial spreading melanomas were positive for galanin and α-MSH, and the latter also showed the highest percentage of positive cells for galanin (mean 35.09 ± 28.16) as well as for α-MSH (mean 67.64% ± 35.38). A positive correlation of 71 % was found for immunostaining of both neuropeptides in melanomas. No significant correlation was observed between galanin expression and age, gender, location of the lesions, Breslow index, Clark level and mitotic index.ConclusionOur study shows the expression of galanin in cutaneous melanoma and its significant correlation with α-MSH immunostaining.     

Expression of the proliferation and apoptosis-associated CAS protein in benign and malignant cutaneous melanocytic lesions

We have examined the expression of the cellular apoptosis susceptibility protein, a nuclear transport factor that plays a role in apoptosis and cell proliferation, in benign and malignant melanocytic lesions. Tissue samples of 55 formalin-fixed, paraffin-embedded melanoma (primary n=32, metastatic n=23) and of 27 control cases (junctional dermal, compound, Spitz, Reed, blue nevi, balloon-cell nevus, lentigo maligna) were analyzed by immunohistochemistry with anti-cellular apoptosis susceptibility antibodies. The percentage of cellular apoptosis susceptibility-positive cells as well as the intensity on a four-point scale was evaluated. In normal skin, expression of cellular apoptosis susceptibility was primarily found in the basal cell layer of the epidermis. Benign melanocytic lesions that stained positive for cellular apoptosis susceptibility (13 of 27) showed a homogeneously distributed staining pattern with a mean of 5+/-12% cellular apoptosis susceptibility positive cells. Five out of 7 lentigo maligna melanoma, 11 out of 12 superficial spreading melanoma and all acrolentiginous (n=7) and nodular (n=6) melanoma showed immunoreactivity of medium (++) to high ( ) intensity. Vertical growth phases of primary cutaneous melanoma stained stronger than horizontally growing cell clusters. All metastases (n= 23) stained strongly positive, the staining pattern being inhomogeneous. Cellular apoptosis susceptibility detection in clinical stages according to UICC showed an increase from 43+/-34% cellular apoptosis susceptibility positive cells in stage I, to 53+/-26% in stage II, 68+/-24% in stage III and 72+/-24% in stage IV, respectively. Because the expression of cellular apoptosis susceptibility correlates predominantly with advanced stages of melanoma, staining with anti-cellular apoptosis susceptibility antibodies may be useful for diagnosis of melanoma and possibly as an immunohistochemical prognostic factor in cutaneous melanocytic lesions.     

IMP‐3 expression in melanocytic lesions

Background: Insulin‐like growth factor‐II mRNA‐binding protein 3 (IMP‐3 ), a member of the insulin‐like growth factor mRNA‐binding protein family, is expressed in several human malignancies, including melanomas. However, the expression of IMP‐3 has not been explored in melanoma in situ, various histologic subtypes of invasive melanomas and atypical Spitz tumors. Methods: IMP‐3 immunostain was performed in 157 melanocytic lesions. Results: Nearly all benign (8/8), dysplastic (8/8) and Spitz nevi (8/9) were negative for IMP‐3. Focal IMP‐3 positivity was observed in 5/12 melanoma in situ and 4/15 superficial melanomas (Breslow depth ≤1 mm). Half (10/20) of deep melanomas (Breslow depth >1 mm) and 25/52 metastatic melanomas demonstrated strong IMP‐3 staining. IMP‐3 expression differs significantly between non‐desmoplastic melanomas (superficial and deep) and benign or dysplastic or Spitz nevi (p = 0.0427, respectively). Four of 23 desmoplastic melanomas expressed IMP‐3 , which was significantly different from deep melanomas (p = 0.0109). IMP‐3 stained 7 of 10 atypical Spitz tumors. The difference between atypical Spitz tumors and Spitz nevi was statistically significant (p = 0.0256). Conclusion: A malignant circumstance, such as non‐desmoplastic melanoma or atypical Spitz tumor, can be inferred when IMP‐3 is expressed, suggesting potential diagnostic value of IMP‐3 in melanocytic lesions. Yu L, Xu H, Wasco MJ, Bourne PA, Ma L. IMP‐3 expression in melanocytic lesions.