A Distinct Pretreatment Immune Gene Signature in Lentigo Maligna Is Associated with Imiquimod Response.

Lentigo maligna (LM) is a common subtype of in situ melanoma on chronically sun-exposed skin, particularly the head and neck of older patients. Although surgery is the standard treatment, there is associated morbidity, and options such as imiquimod cream or radiotherapy may be used if surgery is refused or inappropriate. Complete response rates following imiquimod treatment are variable in the literature. The aim of this study was to evaluate the host immune response both before and following treatment with imiquimod to better identify likely responders. Paired pre- and post-imiquimod treatment specimens were available for 27 patients. Patients were treated with imiquimod 5 days per week for 12 weeks; at 16 weeks, lesions were excised for histological assessment. Of the 27 patients, 16 were responders and 11 failed to clear the disease. PDL1 protein expression was increased, accompanied by a unique gene signature in lesions from patients that subsequently histologically cleared LM by 16 weeks. This comprised 57 upregulated immune genes in signaling networks for antigen presentation, type I interferon signaling, and T-cell activation. This may represent an early responder group to imiquimod, and this unique gene signature potentially can be used as a biomarker of LM response to imiquimod.

Subungual atypical lentiginous melanocytic proliferations in children and adolescents: A clinicopathologic study.

BACKGROUND: Most subungual melanocytic lesions in children are benign, but some are difficult to classify due to prominent lentiginous growth and high-grade cytologic atypia. OBJECTIVE: To characterize the clinicopathologic features of these rare lesions. METHODS: Subungual atypical lentiginous melanocytic proliferations from patients <20 years of age were collected for clinical and histopathologic review. Fluorescence in situ hybridization (FISH) was performed when possible. RESULTS: Eleven patients aged 2-19 years had expanding or darkening longitudinal pigmented streak(s) with or without Hutchinson sign. Microscopically, all revealed predominantly single-cell growth, pagetoid scatter, and poor circumscription. Eight (73%) cases showed focal or poor nesting, and 3 (27%) demonstrated confluence. Nuclear enlargement, hyperchromasia, and angulation were present in 8 (73%) cases, 7 (64%) cases, and 6 (55%) cases, respectively. One of 4 cases tested by FISH was positive. Three lesions recurred locally without other adverse outcome. LIMITATIONS: Small sample size and short clinical follow-up. Two cases were examined in partial biopsies only. CONCLUSION: Some subungual melanocytic lesions in children and adolescents are histologically indistinguishable from adult subungual melanoma in situ. While the biologic potential remains elusive, FISH might aid in risk stratification. Awareness of this rare group of lesions is crucial for facilitating future investigation into its biologic behavior.

An unusual case of desmoplastic melanoma containing an osteoclast-like giant cell-rich nodule.

The authors describe a case of a 5 cm mixed desmoplastic melanoma occurring on the cheek of an 88-year-old white woman. The epidermis showed the features of lentigo maligna. Within the dermis, there was a mixed desmoplastic melanoma with 2 components. The first component consisted of infiltrative malignant spindled cells with prominent stromal fibrosis and had the typical appearance of desmoplastic melanoma. The second component was within the deep half of the tumor and consisted of a densely cellular nodule composed of spindled melanocytes admixed with many osteoclast-like giant cells. There was a peripheral neurotropism and tumor invaded bone. The Breslow thickness was 14 mm. On followup, a sacral metastasis was discovered, which had a similar morphology to the deep cellular nodule. Immunohistochemistry of spindled cells both inside and outside the nodule showed S100 positivity with the absence of other melanocytic markers (HMB-45, Melan-A). Smooth muscle actin and p63 were focally positive. The osteoclast-like giant cells expressed CD68 and MiTF. Array comparative genomic hybridization of the typical desmoplastic melanoma region had a flat profile, whereas the cellular osteoclast-like giant cell­rich region displayed important cytogenetic anomalies, some of which have been previously described in melanomas. The main array comparative genomic hybridization findings were confirmed by fluorescence in situ hybridization using specific probes. The differences in morphology and molecular cytogenetics between the 2 areas suggest that these might represent the progression or emergence of a more aggressive clone within the tumor. Subsequent metastatic spread to the bone may be a result of accumulated cytogenetic abnormalities.

Distribution of MC1R variants among melanoma subtypes: p.R163Q is associated with lentigo maligna melanoma in a Mediterranean population.

BACKGROUND: Cutaneous melanoma tumour is classified into clinicohistopathological subtypes that may be associated with different genetic and host factors. Variation in the MC1R gene is one of the main factors of risk variation in sporadic melanoma. The relationship between MC1R variants and the risk of developing a specific subtype of melanoma has not been previously explored. OBJECTIVES: To analyse whether certain MC1R variants are associated with particular melanoma subtypes with specific clinicohistopathological features. METHODS: An association study was performed between MC1R gene variants and clinicopathological subtypes of primary melanoma derived from 1679 patients. RESULTS: We detected 53 MC1R variants (11 synonymous and 42 nonsynonymous). Recurrent nonsynonymous variants were p.V60L (30·0%), p.V92M (11·7%), p.D294H (9·4%), p.R151C (8·8%), p.R160W (6·2%), p.R163Q (4·2%) p.R142H (3·3%), p.I155T (3·8%), p.V122M (1·5%) and p.D84E (1·0%). Melanoma subtypes showed differences in the total number of MC1R variants (P = 0·028) and the number of red hair colour variants (P = 0·035). Furthermore, an association between p.R163Q and lentigo maligna melanoma was detected under a dominant model of heritance (odds ratio 2·16, 95% confidence interval 1·07-4·37; P = 0·044). No association was found between p.R163Q and Fitzpatrick skin phototype, eye colour or skin colour, indicating that the association was independent of the role of MC1R in pigmentation. No association was observed between MC1R polymorphisms and other melanoma subtypes. CONCLUSIONS: Our findings suggest that certain MC1R variants could increase melanoma risk due to their impact on pathways other than pigmentation, and may therefore be linked to specific melanoma subtypes.

[Mitosis in early invasive malignant melanoma. How reliable is histogenetic classification at stage pT1?]. / Mitosen bei frühinvasiven malignen Melanomen. Wie sicher ist die histogenetische Zuordnung im Stadium pT1?

Since early February 2010 we have been implementing the latest version of the 2009 AJCC Melanoma Staging and Classification in our institution. Since, according to the guidelines for stage pT1 melanomas, the number of mitoses/mm(2) is of particular significance, we have been able to observe a notable shift from pT1a to pT1b. Highlighting the mitotic count as one of the key features of the diagnosis of malignant melanoma, we observed that the major part of stage-switched melanomas belonged to a minimally invasive subset of melanomas previously categorized as pT1a UICC (7(th) edition). A level of reasonable doubt remains regarding the distinct histogenetic classification of mitosis as early stage melanoma with regard to their epithelial or melanocytic origin.

Melanocitoma meníngeo del ángulo pontocerebeloso, ¿Un tumor benigno? / Cerebellopontine angle meningeal melanocytoma: a benign tumor?

Se presenta un paciente con un raro melanocitoma meníngeo del ángulo pontocerebeloso que, tras su extirpación quirúrgica radical, evolucionó en el plazo de un año hacia una melanomatosis meníngea fulminante. Se realiza una revisión bibliográfica en busca de las claves para hacer una aproximación diagnóstica preoperatoria de este tipo de tumor y obtener información sobre su tratamiento y manejo postoperatorio (AU)

We report a case of a rare meningeal melanocytoma in the cerebellopontine angle. One year after tumor gross total removal, the patient suffered a sudden and devastating meningeal melanomatosis. The relevant literature is reviewed looking for the keys to establish preoperative diagnosis and to obtain information about its treatment and postsurgical management (AU)

Chromosomal copy number changes supporting the classification of lentiginous junctional melanoma of the elderly as a subtype of melanoma.

Recently the term lentiginous melanoma of the elderly has been suggested for a pattern of melanocytic neoplasia characterized by frequent occurrence in elderly patients, broad lentiginous growth pattern, with poorly cohesive nesting, suprabasilar extension of melanocytes and moderate cytological atypia. However, there are limited reported cases with follow-up information to confirm the malignant nature of these neoplasms. Using fluorescence in situ hybridization (FISH) targeting chromosomal loci that are frequently found to have copy number changes in melanoma, we evaluated cases of lentiginous junctional melanoma of the elderly in order to compare with the frequencies and patterns of chromosomal aberrations identified in other subtypes of melanoma. Previous studies have shown that by using a FISH assay targeting 6p25, 6q23, 11q13 and CEP6 with previously validated criteria, one could discriminate benign nevi from melanoma with high sensitivity and specificity. In this study, 16 of 19 cases (84%) showed sufficient copy number changes in one of the targeted chromosomal loci to meet FISH criteria for melanoma. A total of 17 control cases of lentiginous junctional nevi tested negative for all criteria. These findings support the classification of this pattern of melanocytic neoplasia as a subtype of melanoma.

Xeroderma pigmentosum and lentigo maligna in identical twins.

Xeroderma pigmentosum (XP) is a rare autosomal recessive genodermatosis. Skin abnormalities result from an inability to repair UV-damaged DNA. Clinically, XP presents with early onset cutaneous changes (severe photosensitivity, actinic keratoses, and telangiectasias) and an increase of developing cutaneous malignancies beginning in early childhood, but lentigo maligna and melanomas are relatively rare. Here we report on homozygote twins in whom there was no positive family history. They showed subnormal physical growth. On ophthalmological examination, both had photophobia and decreased visual acuity. Since birth, several excisions had been performed for skin neoplasms. In one of them a pigmented patch developed over the frontal area which proved to be lentigo maligna and she was referred to a dermato-oncology center. They have been given isotretinoin and physical sunscreen since then. The follow-up period was extended to 2 years and no serious complications occurred from the above treatment. This is an interesting report about XP in twins with the presentation of the rare neoplasm lentigo maligna.

Prevalence of exon 15 BRAF mutations in primary melanoma of the superficial spreading, nodular, acral, and lentigo maligna subtypes.

DNA was extracted from 52 thick primary melanomas and mutations sought in exon 15 of the BRAF (v-raf murine sarcoma viral oncogene homolog B1) gene using denaturing high performance liquid chromatograph (dHPLC) fragment analysis, sequencing, and allele-specific PCR. Exon 15 BRAF mutations were found in 13 of 52 (25%) primary melanomas. These comprised five of 17 (29%) superficial spreading melanomas, three of 11 (27%) nodular melanomas, two of 13 (15%) acral lentiginous melanomas, one of one (100%) mucosal melanoma and two of 10 (20%) lentigo maligna melanomas. In common with other groups, our findings show a relative concentration of the exon 15 BRAF mutation in superficial spreading and nodular melanomas, but add further evidence that this mutation not necessary for malignant transformation of the melanocyte.

Clinical and histopathological characterization of cutaneous melanomas in the melanoblastoma-bearing Libechov minipig model.

Spontaneous animal tumors appear to be highly suitable models to study human oncology and cancer therapy. The aim of this study was to characterize the clinical and histological features of hereditary melanocytic lesions found in the French herd of melanoblastoma-bearing Libechov minipigs (MeLiM) and their Duroc crossbreeds. Clinically, we discriminated between three types of melanocytic skin lesions, which offer a lesion continuum from lentigo to metastatic melanomas. More than 70% of these lesions appear on piglets before they are 3 months old and preferentially on homogeneous black coat piglets. The incidence of melanoma reaches 50% in MeLiM. Most of the highly invasive melanomas regressed spontaneously in the first year of the piglet's life and the regression was followed by hair, skin and iris depigmentation. A histopathological study was conducted according to the human melanoma classification. Except for lentigo maligna, we observed the three main types of human melanoma in swine [superficial spreading melanoma (SSM), nodular or unclassified melanoma] with an excess of SSM (59-67%). The histological events leading to total spontaneous regression are chronologically described. The genetic predisposition, the high incidence of melanoma, the clinical and histopathological features similar to the human disease and the high rate of spontaneous regression offer an opportunity to use this model for studying genetic events controlling melanoma development and regression and the biological mechanisms involved in oncogenesis and anti-cancerous self-defense.

Relationship between DNA mismatch repair genes expression, Ku-genes expression and ploidy-related parameters in the progression of pigmented lesions of the skin.

Defects of DNA repair systems in cutaneous tumours are related to DNA mismatch repair genes (MLH1, MSH2, PMS1, PMS2) and Ku70/80 genes involved in double- strand repair. In this study we investigated the statistical relationship between these systems and DNA-ploidy-related parameters in 19 naevus cell naevi, 23 lentigos maligna, 76 primary melanomas and 31 melanoma metastases, applying the correlation coefficient according to Spearman. In naevi significant correlations were found between Ku70/80 gene expression and some ploidy-related parameters. In lentigos, additionally, some significant correlations between the expression of DNA mismatch repair genes were found. Similar results were demonstrated for primary melanomas. In metastases no one significant correlation between DNA mismatch repair genes and Ku-genes was present. We postulate that DNA mismatch repair genes and Ku70/80 genes are functionally independent and that some of them are able to influence ploidy-related parameters.

Relationship between DNA ploidy-related parameters and the deletions in mismatch repair genes MLH1 and MSH2 in lentigo maligna and malignant melanomas.

Defects in DNA mismatch repair genes MLH1 and MSH2, first described in hereditary nonpolyposis colon cancer (HNPCC), have been postulated to be responsible for malignant transformation in several tumours. To date there are no data on cutaneous tumours. Using a PCR assay it was possible to identify deletions in MSH2 (exonic regions 12 and 13) in 16 of 47 lentigos maligna and in 10 of 36 malignant melanomas. Deletions in MLH1 (exonic regions 15 and 16) were found in 11 of 47 lentigos and in 15 of 36 melanomas. Comparison of DNA ploidy-related parameters between lentigos with and without exonic deletions in MSH2 and MLH1 did not show any significant differences. In contrast, melanomas positive and negative for exons 12 and 13 (MSH2) (26/36 and 10/36, respectively) differed significantly with respect to the percentages of diploid cells (P = 0.0179) and tetraploid cells (P = 0.0042). Comparison of melanomas positive and negative for exons 15 and 16 (MLH1) (21/36 and 15/36, respectively) showed significant differences in the percentage of aneuploid cells between 2c and 4c (P = 0.0141) and tetraploid cells (P = 0.0404). In summary, deletions in DNA mismatch repair proteins MSH2 and MLH1 were present both in lentigo maligna and in melanomas and correlated with DNA ploidy-related parameters in malignant melanomas.

Evaluation of DNA ploidy and degree of DNA abnormality in benign and malignant melanocytic lesions of the skin using video imaging.

BACKGROUND: Making a morphologic distinction between benign and malignant melanocytic tumors of the skin is frequently difficult, especially because "gray zones" between these lesions often exist. DNA image cytometry as an adjuvant method for the diagnosis and prognostic prediction of premalignant lesions and malignant tumors of many other organs is already well established. The aim of this study was to determine whether DNA image cytometry is helpful in distinguishing benign from malignant melanocytic lesions and whether cytometry would give valid information with which to predict the prognoses associated with malignant melanomas. METHODS: DNA image cytometry was performed on 127 benign and 58 primary maligant melanomas of the skin as well as 11 metastatic melanomas, using an enzymatic single cell solution according to a method described by Heiden et al. in Cytometry (1991;12:614-21). RESULTS: DNA aneuploidy was graded by DNA index (DI) and a 2c deviation index (2cDI). In contrast to benign melanocytic lesions (with 16% DNA aneuploidy), primary and metastatic malignant melanomas had significantly higher frequencies of DNA aneuploidy (86% and 73%, respectively). In the degree of DNA aneuploidy, significant differences between benign and malignant melanocytic tumors could be observed. The mean 2cDI of aneuploid benign lesions was 1.0, whereas the primary malignant melanomas had a mean 2cDI of 2.92 and the metastatic melanomas a mean of 6.9. The frequency of DNA aneuploidy increased with Breslow thickness. Twenty-one patients with primary malignant melanoma developed metastases. All metastasizing primary tumors were aneuploid and showed a significantly higher grade of DNA aneuploidy than nonmetastasizing malignant melanomas. Moreover, none of the diploid malignant melanomas developed metastases. CONCLUSIONS: This study reveals that DNA image cytometry is prognostically and diagnostically relevant to the evaluation of melanocytic lesions of the skin. Nevertheless, it cannot be relied on alone to provide enough information for a diagnosis.

Detection of hyperdiploidy and chromosome breakage affecting the 1 (1cen-q12) region in lentigo malignant melanoma (LMM), superficial spreading melanoma (SSM) and congenital nevus (CN) cells in vitro by the multicolor FISH technique.

The centric/pericentric region of chromosome 1 (cen-q 2) of human melanoma cells of different stages of carcinogenicity (superficial spreading melanoma (SSM), lentigo malignant melanoma (LMM)) and premalignant precursor lesions (congenital nevus (CN)) were investigated by fluorescence in situ hybridization (FISH) with tandem DNA probes. The pericentric heterochromatin region 1(q12) is large and highly prone to breakage in contrast to the adjacent centromeric region which is much smaller and less prone to such events. All samples of melanoma cells were obtained from patients and cultivated in vitro. LMM cells showed the highest number of breakage events within the 1q12 region (90% of cells). The number of hyperdiploid cells was not increased in comparison to CN cells. In contrast to LMM cells, SSM cells showed a significant increased number of hyperdiploid cells which were mainly tetrasomic for chromosome 1 (P < or = 0.05). The number of chromosome breaks was not significantly increased in this type of melanoma cells. The spontaneous rates of chromosomal breakage and hyperdiploidy is relatively low in CN cells (1.5-2.5% and 3.2-5.8%, respectively) but these frequencies also differ between CN samples from different patients. These results show that the multicolor FISH technique represents a fast and reliable detection method, distinguishing structural and numerical chromosomal alterations in interphase nuclei. This technique is useful as a histological marker to differentiate between specific tumor subtypes and to investigate the relationship between genomic instability and clinopathological parameters (tumor grading and staging).

Familial cutaneous melanoma and two-mutational-event modeling.

BACKGROUND: According to the Knudson two-mutational-event theory, two mutations at a genetic locus may be required for the development of some cancers. Persons who have inherited a defect in one chromosome and therefore require only one more mutation for cancer development are at a higher risk of manifesting cancer at a younger age than persons without an inherited mutation, who need two acquired "hits." This difference allows one to distinguish familial and sporadic types of the same malignancy by evaluating age of disease onset. METHODS: To study the role of inheritance in the etiology of familial cutaneous melanoma, characteristics of patients with familial versus nonfamilial melanoma were analyzed according to the Knudson two-mutational-event model. RESULTS: The familial versus nonfamilial graphs, based on age of diagnosis, did not support this model. However, there was a statistically significant earlier age of diagnosis for patients with familial melanoma. Melanoma thickness was less (i.e., earlier cancer at possibly younger age) for patients with a positive versus a negative family history. Conversely, linear regression, after adjusting for tumor thickness, showed that patients with hereditary melanoma still manifested earlier ages of diagnosis of melanoma compared with sporadic patients. CONCLUSIONS: Genetic patterns other than the two-step model, additional family-related factors, patient-physician sensitization due to a family history, or a combination of these factors might explain this age difference. More complex multistep modeling of the data may be helpful in better characterizing the genetic patterns of cutaneous melanoma.

Risk of cancer in relatives of patients with cutaneous melanoma.

BACKGROUND: Cutaneous malignant melanoma (CMM) is a recognized feature of the Lynch type II cancer-family syndrome and the Li-Fraumeni's syndrome. A significant contribution of these syndromes to the total burden of CMM would be reflected in an increased risk of nonmelanoma cancers in first degree relatives. METHODS: Pedigrees were taken from 85 patients with CMM using a family history questionnaire. The relative risk of death from all cancers and individual cancers in first degree relatives was calculated. RESULTS: Of the 85 questionnaires, those of 79 patients were completed and of adequate quality for analysis. The first degree relatives of CMM patients showed no increased risk of cancer death, the relative risk of cancer death being 1.0. Six patients (7.6%) had first degree relatives with CMM. One patient had a family history compatible with the dominant transmission of a predisposition to cancer. CONCLUSIONS: It is important to establish whether an increased cancer risk is present in relatives of patients with malignancies so that screening programs may be offered. This study provides little evidence to support seeing relatives for noncutaneous malignancies in the absence of a dominant family history of predisposition to cancers. The increased frequency of CMM in relatives suggests that relatives of CMM patients should be counseled on protection from the sun and examination of the skin for melanoma.