Regulatory T cells in skin lesions and blood of patients with bullous pemphigoid.

BACKGROUND: Although regulatory T cells (Tregs) are affected in several autoimmune skin diseases, only two studies have been performed in patients with bullous pemphigoid (BP) with contrasting results. OBJECTIVE: To characterize Tregs and to determine the serum levels of regulatory cytokines in patients with BP. METHODS: In BP lesional skin, immunohistochemistry and confocal microscopy were performed for CD4(+) , CD25(+) , forkhead/winged helix transcription factor (FOXP3)(+) , transforming growth factor (TGF)-ß(+) and interleukin (IL)-10(+) cells. In addition, the number of CD4(+) CD25(++) FOXP3(+) Tregs in peripheral blood was assessed by flow cytometry, and the levels of TGF-ß and IL-10 were determined in serum samples by enzyme-linked immunosorbent assay before and after steroid therapy. Controls included patients with psoriasis, atopic dermatitis (AD) and healthy donors. RESULTS: The frequency of FOXP3(+) cells was significantly reduced in skin lesions from patients with BP (P < 0.001) compared with psoriasis and AD. Moreover, the number of IL-10(+) cells was lower in BP than in psoriasis (P < 0.001) and AD (P = 0.002), while no differences were observed in the number of TGF-ß(+) cells. CD4(+) CD25(++) FOXP3(+) Treg in the peripheral blood of patients with BP was significantly reduced compared with healthy controls (P < 0.001), and augmented significantly after steroid therapy (P = 0.001). Finally, TGF-ß and IL-10 serum levels were similar in patients with BP compared with healthy controls. However, after therapy, BP patients showed significantly higher IL-10 serum levels than before therapy (P = 0.01). CONCLUSIONS: These data suggest that the depletion of Tregs and of IL-10 in patients with BP may be an important factor in the pathogenesis of the disease.

Favourable prognostic role of regression of primary melanoma in AJCC stage I-II patients.

BACKGROUND: The prognostic significance of regression in primary melanoma has been debated over the past few years. Once it was considered to be a negative prognostic factor, as it may have prevented proper melanoma thickness measurement, therefore affecting the staging of the tumours. For this reason, it was considered to be an indication for sentinel lymph node biopsy (SLNB) in melanoma < 1 mm. OBJECTIVES: To ascertain the utility of SLNB in thin melanoma and to clarify the role of regression in disease-free survival (DFS) and overall survival (OS) in our series. METHODS: We analysed data collected from 1693 consecutive patients with AJCC (American Joint Committee on Cancer) stage I-II melanoma. RESULTS: Globally, SLNB was performed in 656 out of 1693 patients. Regression was present in 349 patients and 223 of them were characterized by thin lesions. SLNB was performed in 104 cases of thin melanoma with regression. The majority of regional lymph node metastases were observed in patients who did not undergo SLNB (89 out of 132). Among the remaining 43 'false negative' patients only three showed regression in the primary. Using the Cox multivariate model, histological regression maintained a significant protective role [hazard ratio (HR) 0·62, P = 0·012 for DFS; HR 0·43, P = 0·008 for OS] when corrected for the principal histopathological and clinical features, despite SLNB. CONCLUSIONS: We confirmed that regression alone should not be a reason to perform SLNB in thin melanoma and, on the contrary, it can be considered a favourable prognostic factor in patients with AJCC stage I-II melanoma.

Melanoma relapse over a pacemaker pocket: case report and integrated management strategies.

We report the first related case of a metastasis from melanoma appeared on a pacemaker device pocket. The stadiation exams showed that this is the only localization of the pathology. The integrated management from both cardiologic and dermatologic surgery was described. It was composed by two interventions, a first time for the implant of a new device contralaterally, and later by the surgical intervention, with exeresis of the lesion, radical lymph node dissection of the axilla and plastic reconstruction. The previous pacemaker implant may hypothetically create a favourable environment for metastatic cells ingrowth. This could be explained by a chronic inflammatory reaction and capsule formation around the device as previously reported, or by a blockage of lymphatic drainage in this specific site.

Flow cytometric analyses of circulating regulatory T cells in patients with dermatitis herpetiformis and other immune mediated dermatoses.

Regulatory T cells (Tregs) play a crucial role by maintaining the peripheral tolerance and inhibiting autoimmunity. In recent years, numerous autoimmune and immune-mediated diseases have been shown to present significant number depletion and/or function impairment of this subset. In the present study, we present a brief overview of the results obtained by our group in association with the centers belonging to the Italian Immunopathology Group, as to the expression levels and biological significance of circulating regulatory CD4+CD25+brightFOXP3+ T cells in a variety of immune-mediated skin diseases (such as psoriasis, scleroderma, bullous pemphigoid and GvHD), together with preliminary results achieved in patients with inflammatory bowel disease-related dermatoses. This review shows that this series of different cutaneous diseases characterised by an immune-mediated pathogenesis, share a significant down-regulation of circulating FOXP3+ Treg cells, whilst the treatment and the achievement of clinical response are generally associated with an opposite phenomenon with up-regulation of Treg cells. Future studies are mandatory to identify the effective role of these modifications in the disease pathogenesis as well as its relationship with the clinical response.

Relevance of multiple basin drainage and primary histologic regression in prognosis of trunk melanoma patients with negative sentinel lymph nodes.

BACKGROUND: Lymphatic drainage to multiple basins (MLBD) is frequently observed in patients with primary melanoma located in the trunk. Conflicting data regarding the prognostic impact of MLBD are reported. OBJECTIVE AND METHODS: We reviewed our case series of 352 patients with trunk melanoma to evaluate the pattern of basin drainage and to analyse whether different basin drainages may have different significance in negative sentinel lymph node (SLN) patients. The presence of single/multiple basin drainage, the status of SLN, the presence of melanoma regression, Breslow thickness, ulceration and type of melanoma were recorded for each patients and correlated to Disease Free Survival (DFS) and Overall Survival (OS). RESULTS: MLBD occurred in 77 patients (21.9%) and single basin lymphatic drainage (SLBD) occurred in 275 patients (79.1%). The presence of metastases in SLN was not significantly different in patients with MLBD compared to those with SLBD (26% vs. 19.6%). No differences in OS and DFS were found in SLBD/MLBD independently from SLN status. However DFS was higher in patients with MLBD and negative SLN (P = 0.0001), in addition, in patients with negative SLN and SLBD disease recurrence was 19% while was only 7% in patients with negative SLN obtained from MLBD (P = 0.03). Multivariate analysis showed that Breslow thickness <2 mm, MLBD pattern and regression of melanoma were favourable variables for DFS of patients with negative SLN. CONCLUSIONS: An accurate study of the drainage basin and of all the SLNs obtained from MLBD is recommended because of the impact in prognosis of melanoma of the trunk.

Melanoma in patients younger than 20 years.

AIM: Melanoma is rare in children and uncommon in adolescents. Clinical and prognostic factors can differ from adult population. There is often a delay in diagnosis and the therapeutic management is not unequivocally established. The aim of this study was to review our monocentric case series to establish the characteristics of the population and the possible different behaviour of the malignancy compared to adults. METHODS: From 1975 to 2011 we selected 36 out of 43 patients with a diagnosis of melanoma before the age of 20. We reported a female predominance, the most common site of primary lesions for both sexes were the lower extremities and according to adulthood population the most common histotype was Superficial Spreading Melanoma. RESULTS: None of our patients presented distant metastasis at diagnosis, but 29.4% showed a progression, and the 17.6% died during the follow-up. A significant difference based on gender was found at the multivariate analysis on Disease free survival as well as Breslow thickness, but only Breslow thickness was the only parameter that maintained a role on survival at multivariate analysis when corrected for gender and age. We performed the sentinel lymph node biopsy in 3 patients and they all resulted negative. CONCLUSION: Despite our small case series we observed some important differences of melanoma in children compared to adults. It remains difficult to establish the prognostic factors in younger melanoma patients. Similar to adults, the detection of melanoma in an early phase of development, with a low Breslow thickness, is the most important prognostic factor.

Mycosis fungoides: disease evolution of the "lion queen" revisited.

Mycosis fungoides (MF), which represents the most common subtype of primary cutaneous T-cell lymphoma (CTCL), is an epidermotropic lymphoma included as an indolent form in the recent WHO/EORTC classification. From a clinical point of view, the classic disease progression usually is slow and takes over years or even decades, and characterized by the evolution from patches to more infiltrated plaques and eventually to tumours or erythroderma. However, the analysis of the MF disease course has been greatly impaired by the rarity of the disease, thus data about the time course of disease progression and pattern of relapse during time are not well known. In this review, a summary of published data on MF large patients cohorts will be presented, together with the results obtained by a retrospective analysis of clinical features and follow-up data of 1,422 MF patients diagnosed and followed-up from 1975 to 2010 in 27 Italian Centres (Italian Study Group for Cutaneous Lymphoma). From a clinical perspective, the amount of data support the relevance of a stage-tailored, differentiated follow-up strategy, in as much as the TNMB staging appears not only to be associated with different progression rates, but also shows as a new finding a relationship with different patterns of disease progression. From a biological point of view, there is the need to understand the molecular basis of the different clinical pathways of disease progression, to be able to potentially identify at an earlier phase of disease evolution, the patients who are more likely to develop erythroderma or tumour-stage progression. In conclusion, if MF is indeed a true "lion queen", as dermatologists we need to be expert and wise tamers to keep it under control.

Erythrodermic CTCL: updated clues to diagnosis and treatment.

Erythroderma is a rare but severe cutaneous condition characterized from a clinical point of view by a complete involvement (as per definition more than 80% body surface) of the skin surface. Pre-existing dermatoses account for about 70% of erythroderma cases, drug reactions are responsible for erythroderma in about 20%, whilst primary cutaneous T-cell lymphoma (CTCL) constitute less than 10% of and are represented by erythrodermic mycosis fungoides and Sézary syndrome. The challenge in these patients is represented by the identification of the etiological agents or conditions, which is clearly of overwhelming relevance in the clinical management and treatment strategies. In recent years, the development of multiparameter flow-cytometry, which allows to identify specific antigens expressed or not expressed on the surface of atypical lymphoid T-cells, and T-cell molecular biology techniques, which are aimed to identify the presence of a clonal T-cell population in the skin and blood on the basis of the finding of rearrangement of the T-cell receptor, have represented relevant useful tool in the differential diagnosis between benign and lymphomatous erythroderma. Moreover, a better understanding of the immunological and molecular pathways in CTCL disease evolution provided the identification of specific therapeutical targets, as well as the constant improvement in the laboratory techniques lead to the development of new and promising agents in CTCL.

Circulating CD4+ CD25brightFOXP3+ regulatory T-cells are significantly reduced in bullous pemphigoid patients.

Bullous pemphigoid (BP) is the most frequent autoimmune bullous skin disease, characterised by auto-antibodies against the hemidesmosome complex. Recently, regulatory T cells (Tregs) have been implicated in the development of several autoimmune diseases; few data are available in BP, failing to demonstrate a role of this subset in disease pathogenesis. The aim of this study was to investigate the expression and phenotypes of different Tregs (CD4+ CD25brightFOXP3+ and CD8+ CD28- cells) in BP to clarify whether the depletion of this subset constitutes one mechanism of tolerance loss. The CD4+ CD25brightFOXP3 and CD8+ CD28- circulating subsets were determined by flow-cytometry in 26 untreated BP patients and compared with a group of age- and sex-matched healthy controls (HC, n = 30). Absolute and percentage values of the CD4+ CD25brightFOXP3+ cells were significantly reduced in BP compared with HC (median CD25brightFOXP3+ expression within CD4+ cells: 1.8 vs. 3.5%, p = 0.002); conversely, BP patients were characterised by a significant expansion of the CD25brightFOXP3- "activated" T-cell subset. CCR4 and CD62L were expressed on the majority of CD4+ CD25brightFOXP3+ cells (75.2 and 82.3%, respectively). No differences in the CD8+ CD28- subset were found between BP and HC. This is the first report showing a significant reduction of circulating CD4+ CD25brightFOXP3+ Treg frequency in BP patients.

Disease progression in melanoma patients with negative sentinel lymph node: does false-negative specimens entirely account for this phenomenon?

BACKGROUND: Sentinel lymph node (SLN) status is the most important prognostic factor for subjects with primary melanoma thicker than 1 mm. OBJECTIVE: We focused our study on patients with disease progression after negative SLN biopsy (SLNB), with the aim of elucidating their clinical and histopathological characteristics, outcome and real incidence of false negative. METHODS: A total of 688 melanoma patients who underwent SLNB (1 May 1998-31 December 2008) were analysed; all patients had Breslow >1 mm or Breslow <1 mm and at least one of the following features: regression, ulceration and/or Clark level IV-V. RESULTS: Progression developed in 114 of 503 negative SLN patients (22.7%); the first metastatic site was regional in 64% and distant in 36% of these cases. Thirty-nine patients had nodal metastases in the SLN basin as first site of progression. High-risk melanomas (P = 0.001) and elderly patients (P = 0.0005) had an increased probability of progression. Women with a higher median age and lower limbs primary melanoma developed mainly regional skin metastases, while an increased probability of distant metastases was demonstrated in patients with primary on the trunk and axillary SLN (P = 0.003, P = 0.001 respectively). Age at diagnosis, Breslow thickness and regression showed a prognostic relevance in univariate and multivariate analyses on disease-free survival and overall survival. CONCLUSIONS: Even if SLN status remains the most important prognostic factor for melanoma patients, progressive disease after a negative SLNB is a relatively frequent event. However, in our opinion, only a part of negative SLNB patients with metastatic spreading should be considered as false negative (7.75%).

Clinical and prognostic reports from 270 patients with multiple primary melanomas: a 34-year single-institution study.

BACKGROUND: Development of more than one primary melanoma in a sole patient is frequent, accounting for 1.2-8.2% of melanoma patients in most recent series. OBJECTIVE AND METHODS: Clinical, histological and epidemiological characteristics of 270 multiple primary melanomas patients were reviewed. RESULTS: Two-hundred and seven patients (76.7%) had two melanomas, whereas in the remaining 63 the number of primary ranged from three to eight; on the whole, 639 multiple primary melanomas were identified. Synchronous melanomas developed more frequently in patients with three or more lesions; median age was significantly lower in the group of patients with more than three melanomas than in the others. Mean Breslow's thickness significantly decreases (P<0.001) from the first (1.77±1.76 mm) to subsequent primaries (0.85±1.25 mm for the second and 0.66±0.48 mm for the third melanoma). Percentage of 'in situ' melanomas was 5.6% as first diagnosis, but increased to 24.8% for the second melanoma; number of nodular melanomas was significantly lower for succeeding diagnosis. AJCC stage at diagnosis showed a statistical prognostic significance, whereas outcome and survival did not depend on the number of primary lesions. Multivariate analysis confirmed the prognostic role of Breslow's thickness, ulceration, gender and patient age, and the better prognosis of patients with multiple melanomas, respect to those with single primary melanoma. CONCLUSIONS: Skin examination and long-term follow-up are mandatory for patients affected by melanoma, with the intent to promptly diagnose not only a disease progression but also possible new primary melanomas.

Th1, Th2, Th17 and regulatory T cell pattern in psoriatic patients: modulation of cytokines and gene targets induced by etanercept treatment and correlation with clinical response.

BACKGROUND: Psoriasis is sustained by pro-inflammatory CD4+ T helper cells mainly belonging to the Th1, Th17 and Th22 lineage. OBJECTIVE: To identify whether treatment with the anti-tumour-necrosis-factor antagonist etanercept is able to induce significant modulations in transcription factor and cytokine mRNA gene expressions related to the different T cell immune response polarization (Th1, Th2, Th17 and regulatory T cells, Treg and to correlate them with clinical response. METHODS: The study population included 19 psoriasis patients treated with etanercept and 19 healthy subjects. Blood samples were collected at baseline and every 4 weeks during treatment. Taqman quantitative real-time polymerase chain reaction was applied to analyse the expression of: Stat-4, T-bet, IL-12p35 and IFN-γ (Th1-related); GATA-3, IL-4 (Th2-related); Stat-3, RORγt, IL-23p19 (Th17-related); Foxp3, IL-2 (Treg-related). Flow cytometry was applied to analyse CD4+CD25+(bright)Foxp3+ cells in peripheral blood. RESULTS: Upregulation of Th1 and Th17 and downregulation of Treg subsets was found at baseline. The response to etanercept could be associated with a significant reversal of the Th1/Th17 activation, and a concomitant upregulation of Th2 and Treg subsets. CONCLUSION: Our data may contribute to a better understanding of the mechanisms underlying the achievement of clinical response in psoriasis and could be helpful for the identification of early predictive markers of response.

Clinico-pathologic features of primary melanoma and sentinel lymph node predictive for non-sentinel lymph node involvement and overall survival in melanoma patients: a single centre observational cohort study.

OBJECTIVE: Completion Lymph Node Dissection (CLND) is the current standard of practice for patients with a positive Sentinel Lymph Node Biopsy (SLNB). Significant morbidity is associated to CLND, so we tried to evaluate which prognostic variables could predict NSLN invasion in SLN-positive patients and their impact on the overall survival (OS). METHODS: A retrospective chart review of 603 patients that had undergone SLNB for melanoma between 2000 and 2009 at our department was done. 100 SLN were positive at the histopathological analysis of SLN. Demographic variables, primary melanoma, SLN pathologic features and results of CLND were analysed. Multivariate logistic regression and OS analyses were carried out to test the prognostic relevance of clinico-pathologic variables on CLND results and disease course. RESULTS: Breslow thickness, ulceration and micro/macrometastatic pattern of SLN invasion carried a significantly independent higher likelihood of NSLN involvement; Starz classification did not maintain a statistical significance in multivariate analysis. Only one patient (4.3%) without adverse prognostic factors showed NSLN involvement, which was found in 33.3% of patients with one and 55.9% with two or more adverse parameters (p = 0.0001). OS analyses confirmed the prognostic significance of these factors. CONCLUSION: Waiting for the results of Multicenter Selective Lymphadenectomy Trial II, our study suggests a clinically useful and easily applicable means of identifying patients with an unfavourable disease course. The presence of one or more adverse factors identifies patients in whom CLND is mandatory to include thereafter in a more strict follow-up program. Moreover, the finding of no adverse prognostic indicators associated to the presence of significant co-morbidities and/or elderly age, could be useful in identifying patients not to treat by CLND.

Regulatory T cells in the skin lesions and blood of patients with systemic sclerosis and morphoea.

BACKGROUND: Systemic sclerosis (SSc) and morphoea are connective tissue diseases characterized by fibrosis of the skin. Although to date their pathogenesis has not been clearly defined, it is thought that autoimmunity may play a role in the development of the skin lesions observed in both these diseases. As regulatory T cells (Tregs) play a key role in the modulation of immune responses, it has recently been suggested that Treg impairment may lead to the development of autoimmune diseases. OBJECTIVES: To investigate the presence of Tregs and their immunomodulatory cytokines, transforming growth factor (TGF)-beta and interleukin (IL)-10, in patients with SSc and morphoea. PATIENTS/METHODS: Fifteen patients with SSc and 15 with morphoea were enrolled. Immunohistochemistry was applied to identify FoxP3+ (forkhead/winged helix transcription factor) Tregs, TGF-beta+ cells and IL-10+ cells in the skin, cytofluorometry to detect CD4+CD25+FoxP3+ Tregs in the blood, and enzyme-linked immunosorbent assays to analyse TGF-beta and IL-10 serum levels. RESULTS: Fewer FoxP3+ Tregs and TGF-beta+ and IL-10+ cells were found in the skin of patients with scleroderma than in controls. Similarly, there were reduced TGF-beta and IL-10 serum levels and fewer circulating CD4+CD25brightFoxP3+ cells in patients with SSc or morphoea, than in controls. CONCLUSIONS: The quantitative reduction of Tregs, together with that of TGF-beta and IL-10 serum levels, may be responsible for the loss of tolerance observed in both SSc and morphoea.

Vitiligo is an independent favourable prognostic factor in stage III and IV metastatic melanoma patients: results from a single-institution hospital-based observational cohort study.

BACKGROUND: The clinical features and the prognostic relevance of vitiligo lesions in melanoma patients are still controversial. This prospective observational study was designed to characterise the clinical features of melanoma-associated vitiligo, to analyse the association with other autoimmune manifestations and to ascertain whether the development of vitiligo lesions carries a prognostic relevance on the clinical course of melanoma. MATERIALS AND METHODS: A total of 2954 consecutive patients have been included; multivariate analyses of distant metastasis-free survival (DMFS) and overall survival (OS) were carried out to ascertain the independent prognostic role of vitiligo as a time-dependent covariate. RESULTS: Vitiligo was demonstrated in 83 of 2954 melanoma patients (2.8%). A significantly higher percentage of autoimmune diseases was demonstrated in vitiligo patients (7 of 83) with respect to patients without vitiligo (80 of 2871) (P = 0.004). Multivariate analyses selected the time-dependent covariate vitiligo as the favourable independent prognostic variable associated to a longer DMFS in stage III and a higher OS in both stage III and stage IV. CONCLUSION: Melanoma-associated vitiligo should be considered as a distinct clinical entity, separate from vitiligo vulgaris, and identifies a subgroup of patients characterised by a high prevalence of immune-mediated diseases and by a favourable prognosis.

Circulating CD4+CD25 bright FOXP3+ T cells are up-regulated by biological therapies and correlate with the clinical response in psoriasis patients.

BACKGROUND: Regulatory T-cell (T(reg)) modulation is one of the potential mechanisms of anti-tumour-necrosis-factor biological agents. However, literature data on psoriasis patients are lacking. OBJECTIVE: To analyse the circulating CD4+CD25(bright)FOXP3+ subset in 30 patients with psoriasis vulgaris/arthropathic psoriasis treated with biologicals and to investigate its relationship with the clinical response. METHODS: The CD25(bright)FOXP3+ expression within the CD4+ subset was determined by multi-parameter flow cytometry at baseline and during treatment. FOXP3 mRNA expression was analysed by real-time reverse transcription PCR. RESULTS: A response was obtained in 16/17 patients (91.1%) with increased CD25(bright)FOXP3+ values and in only 3/11 patients (27.3%) who showed a CD25(bright)FOXP3+ decrease during biological treatment (p = 0.0001). Responders showed significantly higher values than did non-responders as from the first 2 months of treatment (p = 0.0032). A significantly higher posttreatment expression of mRNA FOXP3 was observed in responders compared to non-responders. CONCLUSION: Biological drugs induce a circulating T(reg) up-regulation in a significant percentage of patients; such an increase is an early predictive marker of response.

Reciprocal modulation of circulating CD4+CD25+bright T cells induced by extracorporeal photochemotherapy in cutaneous T-cell lymphoma and chronic graft-versus-host-disease patients.

The mechanisms of action of extracorporeal photochemotherapy (ECP) in cutaneous T-cell lymphoma (CTCL) are poorly understood. Recently, ECP has been shown to induce an increase in regulatory T cell (Treg) expression and functional activities in Graft-versus-host-disease (GvHD), whereas no data are available in CTCL patients. The aim of this study is to evaluate whether ECP is able to modulate the expression levels of the circulating CD4+CD25+bright subset in CTCL patients and whether these modifications are related to the disease course. The patient population included 43 CTCL and 15 chronic GvHD patients treated by ECP at our institutions since 1992. The expression of the circulating CD4+CD25+bright subset was analysed at baseline and sequentially during treatment by flow-cytometry. Fifty healthy donors were used as controls. The baseline circulating CD4+CD25+bright percentage values in CTCL (median: 4.3 percent) were similar to those of healthy donors, whereas GvHD showed significantly lower values (median: 1.5 percent; p<0.001). During treatment, CTCL patients were characterised by an early decrease (from 4.3 percent to 2.4 percent median after 6 months). The CD4+CD25+bright decrease was associated to the disease course, as it occurred in 91.3 percent of responding but in only 25 percent of PD patients (p=0.0001). On the other hand, a significant increase of CD4+CD25+bright cells was observed in GvHD. ECP induces a reciprocal modulation of the circulating CD4+CD25+bright cells in CTCL and GvHD, with a downregulation in CTCL potentially associated with the response mechanisms.

CDKN2A mutations and MC1R variants in Italian patients with single or multiple primary melanoma.

We evaluated the contribution of germline CDKN2A mutations and MC1R variants to the development of melanoma in a hospital-based study of single (SPM, n = 398) and multiple primary melanoma (MPM, n = 95). The overall frequency of CDKN2A mutations was 15.2%, and four-fold higher in MPM than in SPM cases (OR = 4.27; 95% CI 2.43-7.53). The likelihood of identifying a CDKN2A mutation increased with family history of melanoma and younger age at diagnosis in MPM cases. Compared to SPM patients, the risk of harboring a CDKN2A mutation rose as the number of primary melanomas increased and was not influenced by family history. The G101W and E27X founder mutations were the most common. Several other mutations (W15X, Q50X, R58X, A68L, A127P and H142R) were detected for the first time in Italian patients. One novel mutation, T77A, was identified. Several non-coding variants with unknown functional significance were also found (5'UTR -25C > T, -21C > T, -67G > C, IVS1 +37G > C); the novel 5'UTR -21C > T variant was not detected in controls. The CDKN2A A148T polymorphism was more frequent in MPM patients than in the control population (15.7% versus 6.6%). Compared to the SPM patients, MPM cases had a 2-fold increased probability of being MC1R variant carriers and a higher probability of carrying two or more variants. No specific association was observed between the type of variant and the number of melanomas, suggesting that the number rather than the type of MC1R variant increases the risk of MPM. We observed no interaction between CDKN2A status and the presence of MC1R variants. The high frequency of CDKN2A mutations in our MPM cases, independent of their family history, is of relevance to genetic counseling and testing in our population.