T regulatory cells mediate immunosuppresion by adenosine in peripheral blood, sentinel lymph node and TILs from melanoma patients.

T regulatory cells (Tregs), involved in tumour tolerance, can generate Adenosine by CD39/CD73 surface enzymes, which identify four Tregs subsets: CD39+CD73- nTregs, CD39+CD73+ iTregs, CD39-CD73+ oTregs and CD39-CD73- xTregs. In melanoma patients, increased Tregs levels are detected in peripheral blood (PB), sentinel lymph node (SLN) and tumour infiltrating lymphocytes (TILs), but Adenosine role was not investigated yet. We examined total Tregs and Adenosine subsets in PB, SLN and TILs from melanoma patients (n = 32) and PB from healthy donors (HD; n = 10) by flow cytometry. Total Tregs significantly increased in stage III-IV patients PB, in SLN and TILs, as compared to HD/stage I-II patients. Tregs subsets analyses showed that: 1) PB nTregs significantly increased in SLN and decreased in TILs; 2) iTregs significantly increased in stage III-IV patients PB and further significantly increased in SLN and TILs; 3) PB oTregs and xTregs significantly decreased in SLN and TILs. Patients clinical features did not significantly influence total Tregs, except SLN excision order. Results confirmed Tregs role in melanoma progression and indicate Adenosine generation as a novel escape mechanism, being nTregs and iTregs increased in PB/SLN/TILs.

CD4+FOXP3+ T regulatory cells decrease and CD3+CD8+ T cells recruitment in TILs from melanoma metastases after electrochemotherapy.

Electrochemotherapy (ECT) represents an effective local treatment for skin unresectable melanoma metastases with high overall objective response rate. ECT is based on the combination of anti-neoplastic drugs administration and cancer cells electroporation. Whether ECT can also activate the immune system is a matter of debate, however a significant recruitment of dendritic cells in melanoma treated metastases has been described. Herein we investigated immediate and late effects of ECT treatment on T cell subsets in ECT-treated lesions by fluorescent immunohistochemistry. Biopsies from melanoma patients (n = 10) were taken before ECT (t0), at d1 and d14 from treatment. At t0, CD3+CD4+ T cells were the most represented T cells, well detected in the perilesional dermis, particularly at tumour margin, while CD3+CD8+ T cells were less represented. CD4+FOXP3+ T regulatory (Treg) cells were present in the perilesional dermis and within the lesion. ECT induced a significant decrease of CD4+FOXP3+ Treg cells percentage in the perilesional dermis, observed at d1 and at d14 (p < 0.001). CD3+CD8+ T cells frequency significantly increased at d14 from treatment in the perilesional dermis (p < 0.001). Furthermore calreticulin translocation to the plasma membrane, a hallmark of immunogenic cell death, was observed in metastatic cells after ECT. The data reported here confirm that ECT induces a local response, with a lymphoid infiltrate characterized by CD4+FOXP3+ Treg cells decrease and CD3+CD8+ T cells recruitment in the treated lesions. These results might contribute to design novel combinational therapeutic approaches with ECT and immunotherapy in order to generate a systemic long-lasting anti-melanoma immunity.

Treatment efficacy with electrochemotherapy: A multi-institutional prospective observational study on 376 patients with superficial tumors.

BACKGROUND: Cutaneous metastases represent a therapeutic challenge. An increasing body of experience suggests that electrochemotherapy (ECT) provides effective tumor control, although its evidence basis should be strengthened. METHODS: This prospective, multicenter, observational study enrolled patients with superficial metastases, who underwent ECT at 10 centers between 2008 and 2013. Outcomes included adherence to European Standard Operating Procedures of ECT (ESOPE), tumor response, local progression-free survival (LPFS), toxicity and patient-reported outcomes (PROs, EORTC QLQ-C30 plus an 8-item questionnaire). RESULTS: We enrolled 376 eligible patients. Tumor histotype distribution was as follows: melanoma, 56%; squamous cell carcinoma, 11%; Kaposi sarcoma, 11%; breast carcinoma, 8%; basal cell carcinoma, 6%; soft tissue sarcomas, 3%; others, 5%. We registered 1304 target tumors (median size 1 cm). Treatment adhered to ESOPE in 88% of patients as to the route of drug administration, and in 70% as to electrode application. The procedure was mainly performed under sedation (64.6%) and by using intravenous chemotherapy (93.4%). Tumor response rate at 60 days was 88% (complete, 50%). Small tumor size predicted complete response achievement (OR 2.24, p = 0.003), higher LPFS (HR 0.68, p = 0.004) and improved PROs (Global Health Status, p < 0.001; wound bleeding, p < 0.001; healing, p = 0.002; and aesthetics, p < 0.001). Skin toxicity (grade ≥3, 7.8%) was lower in patients with tumors <2 cm (p≤0.001). One-year LPFS was 73.7% (95%CI 68.4-78.3). CONCLUSIONS: ECT represents a valuable skin-directed therapy across a range of malignancies. The most frequently applied treatment modality is intravenous chemotherapy under sedation. Small tumor size predicts durable tumor control, fewer side-effects and better PROs.

Effect of acetazolamide on post-NIV metabolic alkalosis in acute exacerbated COPD patients.

OBJECTIVE: Non-invasive ventilation (NIV) is an effective treatment in patients with acute exacerbation of COPD (AECOPD). However, it may induce post-hypercapnic metabolic alkalosis (MA). This study aims to evaluate the effect of acetazolamide (ACET) in AECOPD patients treated with NIV. PATIENTS AND METHODS: Eleven AECOPD patients, with hypercapnic respiratory failure and MA following NIV, were treated with ACET 500 mg for two consecutive days and compared to a matched control group. Patients and controls were non invasively ventilated in a bilevel positive airway pressure (BiPAP) mode to a standard maximal pressure target of 15-20 cmH2O. RESULTS: ACET intra-group analysis showed a significant improvement for PaCO2 (63.9 ± 9.8 vs. 54.9 ± 8.3 mmHg), HCO3- (43.5 ± 5.9 vs. 36.1 ± 5.4 mmol/L) and both arterial pH (7.46 ± 0.06 vs. 7.41 ± 0.06) and urinary pH (6.94 ± 0.77 vs 5.80 ± 0.82), already at day 1. No significant changes in endpoints considered were observed in the control group at any time-point. Inter-group analysis showed significant differences between changes in PaCO2 and HCO3- (delta), both at day 1 and 2. Furthermore, the length of NIV treatment was significantly reduced in the ACET group compared to controls (6 ± 8 vs. 19 ± 19 days). No adverse events were recorded in the ACET and control groups. CONCLUSIONS: ACET appears to be effective and safe in AECOPD patients with post-NIV MA.

SOX2 regulates self-renewal and tumorigenicity of human melanoma-initiating cells.

Melanoma is one of the most aggressive types of human cancer, characterized by enhanced heterogeneity and resistance to conventional therapy at advanced stages. We and others have previously shown that HEDGEHOG-GLI (HH-GLI) signaling is required for melanoma growth and for survival and expansion of melanoma-initiating cells (MICs). Recent reports indicate that HH-GLI signaling regulates a set of genes typically expressed in embryonic stem cells, including SOX2 (sex-determining region Y (SRY)-Box2). Here we address the function of SOX2 in human melanomas and MICs and its interaction with HH-GLI signaling. We find that SOX2 is highly expressed in melanoma stem cells. Knockdown of SOX2 sharply decreases self-renewal in melanoma spheres and in putative melanoma stem cells with high aldehyde dehydrogenase activity (ALDH(high)). Conversely, ectopic expression of SOX2 in melanoma cells enhances their self-renewal in vitro. SOX2 silencing also inhibits cell growth and induces apoptosis in melanoma cells. In addition, depletion of SOX2 progressively abrogates tumor growth and leads to a significant decrease in tumor-initiating capability of ALDH(high) MICs upon xenotransplantation, suggesting that SOX2 is required for tumor initiation and for continuous tumor growth. We show that SOX2 is regulated by HH signaling and that the transcription factors GLI1 and GLI2, the downstream effectors of HH-GLI signaling, bind to the proximal promoter region of SOX2 in primary melanoma cells. In functional studies, we find that SOX2 function is required for HH-induced melanoma cell growth and MIC self-renewal in vitro. Thus SOX2 is a critical factor for self-renewal and tumorigenicity of MICs and an important mediator of HH-GLI signaling in melanoma. These findings could provide the basis for novel therapeutic strategies based on the inhibition of SOX2 for the treatment of a subset of human melanomas.

The number of excised lymph nodes is associated with survival of melanoma patients with lymph node metastasis.

BACKGROUND: Although the number of excised LNs has been associated with patient prognosis in many solid tumors, this association has not been widely investigated in cutaneous melanoma. This study aims to evaluate the association between the number of excised regional lymph nodes (LNs) and melanoma-specific survival. PATIENT AND METHODS: Clinico-pathological data from 2507 patients with LN metastasis treated at nine Italian centers were retrospectively collected. RESULTS: The number of excised LNs correlated with younger age (P < 0.001), male sex (P < 0.001), neck LN field (P < 0.001), LN micrometastasis (P < 0.001) and number of positive LNs (P < 0.001). The number of excised LNs was an independent prognostic factor (HR = 0.85; P = 0.002) after adjustment for other staging features. Upon subgroup analysis, the number of excised LNs had a significant prognostic value in patients bearing 1.01-2.00 mm (HR = 0.79; P = 0.032) and 2.01-4.00 mm (HR = 0.71; P < 0.001) thick melanomas, primary tumors showing ulceration (HR = 0.86; P = 0.033) and Clark level V of invasion (HR = 0.86; P = 0.010), LN micrometastasis (HR = 0.83; P = 0.014) and two to three positive LNs (HR = 0.71; P = 0.001). Finally, this study investigated the influence of the number of excised LNs on patient staging: only when ≥11 nodes were excised the AJCC N stage could stratify prognosis (P < 0.001). Considering the number of excised LNs for each lymphatic field, at least 14, 11, 10 and 12 LNs were needed to stage patients according to the AJCC N stage after a lymphadenectomy of the neck, axilla, inguinal and ilioinguinal LN fields, respectively. CONCLUSIONS: The number of excised LNs can be considered for risk stratification of patients with regional LN metastasis from cutaneous melanoma. We demonstrated that a minimum number of LNs is required for the correct staging of patients. Further research is needed to evaluate the effectiveness of the minimum number of LNs to be dissected.

Surgical management of melanoma: an EORTC Melanoma Group survey.

OBJECTIVES: The objective of the article is to explore the surgical practices and views in the treatment of melanoma within members and non-members of the EORTC Melanoma Group (MG) during the years 2003-2005. METHODS: An e-mail questionnaire (see appendix) developed within the EORTC MG was sent to all melanoma units (MUs) of the EORTC (180) and to selected international centres between 2003 and 2005. The questionnaire investigated the different practices regarding surgical management of melanoma patients at all stages. RESULTS: A total of 75 questionnaires were returned from centres in Europe (70), Israel (3), Australia (1) and the United States (1). Resection margins on primary melanoma vary according to AJCC 2002 staging. Sixty three of 75 MUs perform Sentinel node biopsy. Modified radical neck dissection is performed in 82% of MUs for macrometastases and in 80% of MUs for micrometastases. Most MUs surveyed perform all three levels of Berg axillary dissection whether for macrometastases (79%) or micrometastases (62%). An ilio inguinal-obturator dissection is proposed with macrometastases (41% of MUs), whereas 33% of MUs perform a pelvic dissection only if the Cloquet node is positive. Twenty five of 75 MUs perform an isolated limb perfusion with a therapeutic indication; three also as an adjuvant. The majority of MUs perform surgery for distant metastases including superficial (53 of 75 [71%]) or solitary visceral metastases (52 of 75[69%]) or for palliation (58 of 75[77%]). CONCLUSION: The adequacy of surgery appears to be the most important milestone in the therapeutic approach of melanoma. Even if surgery is fundamental in the different stages of the disease, there is quite a variability concerning the extension of the surgical treatment related to primary and lymphnodal disease. Phase III randomised trials have shown that wide margins, elective lymph node dissections, and prophylactic isolated limb perfusions have not improved survival and cannot be considered the standard of care in the routine management of primary melanoma. The surgical subgroup of the EORTC Melanoma Group is developing a new version of the surgical survey questionnaire including new treatment modalities like isolated limb infusion and electrochemotherapy, which were not frequently in use some years ago, to obtain new data to be compared to the nearly ten-year-old data.

WIP1 phosphatase modulates the Hedgehog signaling by enhancing GLI1 function.

The Hedgehog-GLI (HH-GLI) signaling plays a critical role in controlling growth and tissue patterning during embryogenesis and is implicated in a variety of human malignancies, including those of the skin. Phosphorylation events have been shown to regulate the activity of the GLI transcription factors, the final effectors of the HH-GLI signaling pathway. Here, we show that WIP1 (or PPM1D), an oncogenic phosphatase amplified/overexpressed in several types of human cancer, is a positive modulator of the HH signaling. Mechanistically, WIP1 enhances the function of GLI1 by increasing its transcriptional activity, nuclear localization and protein stability, but not of GLI2 nor GLI3. We also find that WIP1 and GLI1 are in a complex. Modulation of the transcriptional activity of GLI1 by WIP1 depends on the latter's phosphatase activity and, remarkably, does not require p53, a known WIP1 target. Functionally, we find that WIP1 is required for melanoma and breast cancer cell proliferation and self-renewal in vitro and melanoma xenograft growth induced by activation of the HH signaling. Pharmacological blockade of the HH pathway with the SMOOTHENED antagonist cyclopamine acts synergistically with inhibition of WIP1 in reducing growth of melanoma and breast cancer cells in vitro. Overall, our data uncover a role for WIP1 in modulating the activity of GLI1 and in sustaining cancer cell growth and cancer stem cell self-renewal induced by activation of the HH pathway. These findings open a novel therapeutic approach for human melanomas and, possibly, other cancer types expressing WIP1 and with activated HH pathway.

'Animal-type' melanoma of the scalp with satellitosis and positive sentinel nodes in a 4-year-old child: case report and review of the literature.

BACKGROUND: Although showing a rapidly rising incidence, paediatric melanoma is relatively rare, accounting for 1-4% of all cases of melanoma and for 1-3% of all paediatric malignancies. The overall survival rate in paediatric patients seems to be similar to that recorded in adults. 'Animal-type' melanoma (ATM) is a rare melanoma subtype, occurring both in childhood and in adults, that shows a close histological resemblance to the heavily pigmented melanocytic tumours observed in grey and white horses. CASE PRESENTATION: We present a case of ATM of the scalp with satellitosis and two positive sentinel nodes in a 4-year-old male child. No other tumour deposits were found in the subsequent regional lymphadenectomy; the patient has been tumour free for 30 months. CONCLUSIONS: We treated our case of ATM in a child as the other types of paediatric melanoma, therefore as an adult melanoma. ATM is generally considered a neoplasm with an indolent course, that occasionally shows an aggressive behaviour, and patient deaths of ATM have been reported. Due to the rarity of ATM, further studies are needed to better define the biological behaviour of this particular melanoma subtype and the therapeutic and follow-up strategies.

Familial and sporadic melanoma: different clinical and histopathological features in the Italian population - a multicentre epidemiological study - by GIPMe (Italian Multidisciplinary Group on Melanoma).

BACKGROUND: Having a familial member affected by cutaneous melanoma is a risk factor for this neoplasm. Only a few epidemiological case-control studies have been carried out to investigate whether familial and sporadic melanomas show different clinical and histopathological features. OBJECTIVE: The aim of this study was to evaluate eventual different features and risk factors in subjects affected by familial and sporadic cutaneous melanoma. METHODS: A case-control multicentre study interesting 1407 familial (n = 92) and sporadic (n = 1315) melanomas in the Italian population. The analysis was made using t-test for continuous variables and chi-squared test for categorized ones. The variables which have shown statistically significant differences in the two groups in the univariate analysis were included in a multivariate model. RESULTS: The results showed some main significantly clinical differences between the two groups investigated: earlier age at diagnosis, a greater proportion of sunburns and a higher number of naevi were observed for the familial cases compared with sporadic ones. Nevertheless, we did not find a diagnostic anticipation in familial melanomas, in fact the invasion level and the thickness of melanomas was similar in the two groups. CONCLUSION: Some relevant clinical differences are observed between the two groups examined. The familial melanoma members, although carriers of constitutional risk factors, are not careful enough to primary and secondary prevention.

Simultaneous care and melanoma: preliminary report about the psychoncological approach.

AIM: The main aim of the study was to investigate the efficacy of a "take-in- charge" model of advanced stage melanoma patients by a multidisciplinary team and highlight the psychological patterns of the disease. METHODS: The study sample involved 44 patients, 27 females and 17 males, who were given a "Questionnaire on Health Status SF-12" which provides two synthetic indexes, one related to physical health PCS-12, and the other to mental health MCS-12. The statistical data was collected through a preliminary analysis of principal components P.C. A., carried out with SPSS software. RESULTS: Comparing the scores obtained by the PCS and MCS indexes, the mean score is low: 6.52 out of 10 for PCS and 3.23 out of 10 for MCS. At first consultation, there is evidence which supports patients' need for psycho-oncological support. By dividing the sample patients into two subgroups, cutaneous melanoma and visceral melanoma, it should be noted that the first group obtained a mean of 4.75 for PCS and 3.77 for MCS and the second group 7.53 for PCS and 2.92 for MCS respectively. Therefore, the results show, at first consultation, a more complex situation for patients with cutaneous melanoma. CONCLUSION: The results of the study highlight the need to supply some form of psycho-oncological support to help patients while they adapt to the disease. Furthermore, different problems and different coping styles also emerged depending on whether the patient has cutaneous or visceral melanoma. The study therefore demonstrates the need to take into account such variables when devising a personal care system centered on the patient.

Sphingosine 1-phosphate induces differentiation of adipose tissue-derived mesenchymal stem cells towards smooth muscle cells.

Sphingosine 1-phosphate (S1P) is a bioactive sphingolipid which regulates multiple biological parameters in a number of cell types, including stem cells. Here we report, for the first time, that S1P dose-dependently stimulates differentiation of adipose tissue-derived mesenchymal stem cells (ASMC) towards smooth muscle cells. Indeed, S1P not only induced the expression of smooth muscle cell-specific proteins such as alpha-smooth muscle actin (alpha SMA) and transgelin, but also profoundly affected ASMC morphology by enhancing cytoskeletal F-actin assembly, which incorporated alpha SMA. More importantly, S1P challenge was responsible for the functional appearance of Ca(2+) currents, characteristic of differentiated excitable cells such as smooth muscle cells. By employing various agonists and antagonists to inhibit S1P receptor subtypes, S1P(2) turned out to be critical for the pro-differentiating effect of S1P, while S1P(3) appeared to play a secondary role. This study individuates an important role of S1P in AMSC which can be exploited to favour vascular regeneration.

Dermatofibrosarcoma protuberans in childhood: two case reports and review of the literature.

Dermatofibrosarcoma protuberans (DFSP) is a rare skin cancer with intermediate malignancy, characterized by a progressive local growth and a propensity for local recurrence. DFSP is most frequent in adults; however, in recent years, DFSP in childhood emerged to be more common than previously believed. Unfortunately DFSP in children may be misdiagnosed, leading to a delay in the treatment. The authors report two cases of childhood DFSP with unusual clinical presentation: a congenital nodular variant and an atrophic variant developed at 2 years of age, both with acral localization. They highlight the importance of an early diagnosis by pediatricians and dermatologists to ensure an appropriate complete excision and reduce the risks of recurrences.

[Sentinel lymph nodes in cutaneous melanoma: the experience in the Florence area]. / Linfonodo sentinella nel melanoma cutaneo: l'esperienza nell'area fiorentina.

In the period 1997-2001, 466 sentinel lymph nodes from 342 lymphatic basins in 322 melanoma patients were examined at the Health Unit of Florence. The lymphatic mapping was performed through pre-operative lymphoscintigraphy using technetium-labelled nano-colloid, intradermal injections of vital blue dye and intra-operative gamma-probe. The examined patients were 182 females and 140 males. Sentinel lymph node was one in 65.2% of cases; two sentinel lymph nodes were detected in 27% of cases and more than 2 sentinel nodes were detected in 7.8% of cases. Melanoma metastases in one or more sentinel lymph nodes were found in 61/322 patients (18.9%). Lymphatic basins resulted to be involved by melanoma metastases were 64/342 (18.7%); sentinel lymph nodes containing metastatic melanoma deposits were 73/466 (15.6%). No metastasis was found in patients with melanoma thickness < or = 1 mm. One or more positive sentinel lymph nodes were found in 7.5% of patients with melanoma thickness > 1.00 and < or = 1.50 mm, in 27.7% of patients with melanoma > 1.50 and < or = 3.00 mm, in 38.2% of patients with melanoma > 3.00 and < or = 4.00, and in 60.7% of patients with melanoma > 4.00 mm. Frozen section analysis of sentinel lymph nodes, performed in 59/61 patients with nodal metastases, detected nodal involvement in 21 patients (35.6%). Metastases were identified by routine hematoxylin-eosin staining in 57/64 positive lymphatic basins; in 7 cases (11%) metastases were detected by immunohistochemical stainings (S100 and HMB-45). A nodal nevus was found in 3/466 sentinel lymph nodes (0.6%). Our data are analyzed and compared to previously data of the literature. The value of frozen section analysis and the major problems in the diagnosis of melanoma micrometastases in sentinel lymph nodes are discussed. The importance of the sentinel node biopsy for the detection of occult metastases and for the correct staging of melanoma patients are stressed, according to the new TNM melanoma classification.

Microsatellite analysis in cutaneous malignant melanoma.

The status and relevance of repetitive nucleotide sequences or microsatellite alterations in sporadic cutaneous melanoma has not been fully clarified. In this study we evaluated the presence of microsatellite alterations in a series of sporadic primary and metastatic melanomas in order to discover which genetic events may have a pathogenetic role in the development of this disease. Tumour samples were obtained from 21 patients with sporadic cutaneous melanoma, and from eight corresponding positive sentinel lymph nodes and one corresponding in-transit metastasis. In each specimen, selected neoplastic cells were procured by laser-assisted microdissection. Polymerase chain reaction-based microsatellite analysis was performed using a panel of 11 microsatellite markers, located at chromosome 2p, 4q, 9p, 16q, 17p and 21q. Overall, we found microsatellite alterations in five (23.8%) melanomas. Of these, one case showed alteration at marker D2S2182 and one at marker D17S261, whereas in another case alterations at three loci, D2S2182, D2S2291 and D9S171, were found. The fourth patient demonstrated an alteration at locus D9S171 both in the primary tumour and in the histologically positive sentinel lymph node. The fifth case was characterized by alterations at D2S2182 and at D17S250, whereas the corresponding in-transit metastasis showed the same alterations as the primary tumour and an additional alteration at IFN alpha. In conclusion, our study confirms previous observations that cutaneous melanomas demonstrate microsatellite alterations, although such instability occurs at a lower frequency than specific mismatch repair defects. Genetic analysis of metastatic lesions revealed that the same microsatellite alterations as in the primary tumour are seen, but additional genetic changes may develop during disease progression.

Keloids and hypertrophic scars of Caucasians show distinctive morphologic and immunophenotypic profiles.

The aim of this study was to identify possible morpho-phenotypic differences between keloids (K) and hypertrophic scars (HS) in a Caucasian population. Young HS (< or =1 year of age) presented a high number of diffusely distributed spindle-shaped cells (alpha-smooth-muscle actin+ and fibronectin+). Fully developed HS (> 1 year of age and <3 years of age) were characterized by the frequent presence of distinct collagenous cellular nodules (cells: alpha-smooth-muscle actin+ and fibronectin+). Old HS (> or =3 years of age) showed widespread collagenization phenomena. The histological profile of K was not related to the age of the lesion and was characterized by the almost constant presence of abnormally thick, hyalinized collagen fibers, the presence of collagenous cellular nodules, and variable--albeit lower than in HS-- expression of alpha-smooth-muscle actin and fibronectin. Ultrastructurally, myofibroblasts were the predominant cell type in young and fully developed HS and in K. The immune-cell infiltrate was composed of CD3+, CD45RO+, CD4+, human lymphocyte antigen (HLA)-DR+, and lymphocyte function associated antigen (LFA)-1+ T lymphocytes, strictly associated with CD1a+/ CD36+, HLA-DR+, and intercellular adhesion molecule (ICAM)-1+ dendritic cells, both in HS and K. However, different amounts of immune cells were observed in relation to the type and age of the lesion, and these findings support the hypothesis that cell-mediated, major histocompatibility complex (MHC)-class II-restricted immune responses play an important role in the development of HS and K.

Inducible nitric oxide synthase expression in benign and malignant cutaneous melanocytic lesions.

Nitric oxide (NO) is synthesized by nitric oxide synthases (NOS) and plays an important role in tumour growth. In this study, inducible NOS (iNOS) expression was evaluated by immunohistochemistry in 34 melanocytic naevi (13 common melanocytic naevi, six Spitz naevi, and 15 so-called 'dysplastic naevi'), ten cutaneous melanomas in situ, 50 stage I invasive melanomas, and eight subcutaneous metastases of melanoma. In addition, four samples of melanocytic naevi and four samples of invasive melanomas were collected in order to perform western blot and northern blot analysis. By immunohistochemistry, melanocytic naevi never expressed iNOS. Among cases of melanoma in situ, two were negative, seven displayed staining in less than 20% of melanoma cells, and positivity was observed in 21-50% of melanoma cells in only one case. iNOS expression was detected in 46 out of 50 invasive melanomas (92%). Among these cases, 18 showed positivity in less than 20% of melanoma cells, 18 showed positivity in 21-50% of melanoma cells, and ten showed iNOS expression in more than 50% of cells. Statistical analysis revealed a significant difference in iNOS expression between melanocytic naevi and cutaneous melanomas (p<0.001). In addition, iNOS expression was significantly higher in invasive melanomas than in melanomas in situ (p=0.01). Among primary cutaneous melanomas, no significant correlation was found between iNOS expression and histopathological parameters (histotype, level, thickness and presence of regression/inflammatory infiltrate) and disease-specific survival. In subcutaneous melanoma metastases, iNOS expression was diffuse in more than 50% of cells. Statistical analysis revealed that subcutaneous melanoma metastases showed greater iNOS immunoreactivity than invasive melanomas (p=0.02). Molecular analyses confirmed that iNOS mRNA and protein were highly expressed in melanoma samples. In conclusion, iNOS was constantly absent in melanocytic naevi, whereas it was frequently expressed in melanomas, with up-regulation of the enzyme paralleling tumour progression. These data suggest that iNOS may play a role in the malignant transformation of melanocytes and in tumour growth. In addition, iNOS may be useful as an immunohistochemical marker for malignant melanocytic lesions.

Radioisotopic lymphatic mapping of the sentinel node in melanoma: importance of immunohistochemistry.

BACKGROUND: Elective lymph node dissection (ELND) for patients with malignant melanoma is still controversial. A possible alternative could be biopsy of the first tumor draining lymph node, the sentinel node (SN), which can be identified by means of radionuclide techniques. AIM: Our study was undertaken to assess the accuracy of lymph node biopsy and to stress the importance of immunohistochemistry (IHC) in the pathological assessment of the SN for improved staging of the primary tumor. METHODS: We performed lymphoscintigraphy (LS) in 183 melanoma patients (89 with melanoma of the legs, 11 of the arms and 83 of the trunk). Our protocol consisted of preoperative peritumoral i.d. injection of 99mTc-labeled microcolloid to define the regional lymphatic basin and identify the sentinel node by means of planar scintigraphy. In 147 of the 183 cases a gamma probe (GP) was used during surgery to trace the SN. Vital blue dye was used during surgery in all cases. The SNs were excised for pathological examination. The pathological status of the SN was defined by means of examination of frozen sections, hematoxylin-eosin staining and immunohistochemistry for S-100 and HMB-45 MAb. RESULTS: At least one separate focus of activity was identified by LS in 182 out of 183 patients; in all 147 cases where a GP was used, it was successful in tracing the SN. LS with cutaneous mapping of the SN successfully guided the surgical excision in 177 of the 183 cases; in the 7 remaining cases, i.e. 7 out of 83 cases with SNs in the axillary basin, GP was not used and no elective node dissection was performed. Metastases were found in 39 of these 177 cases. In all 39 cases the SNs were the only positive nodes in the basin. Of the 39 metastases 18 were identified by means of frozen section, 12 by means of hematoxylin-eosin, and 9 by means of immunohistochemistry. We therefore emphasize the importance of immunohistochemistry in the pathology of LS for improved staging of the primary tumor.