Genetic alterations in RAS‐regulated pathway in acral lentiginous melanoma

Studies integrating clinicopathological and genetic features have revealed distinct patterns of genomic aberrations in Melanoma. Distributions of BRAF or NRAS mutations and gains of several oncogenes differ among melanoma subgroups, while 9p21 deletions are found in all melanoma subtypes. In the study, status of genes involved in cell cycle progression and apoptosis was evaluated in a panel of 17 frozen primary acral melanomas. NRAS mutations were found in 17% of the tumors. In contrast, BRAF mutations were not found. Gains of AURKA gene (20q13.3) were detected in 37.5% of samples, gains of CCND1 gene (11q13) or TERT gene (5p15.33) in 31.2% and gains of NRAS gene (1p13.2) in 25%. Alterations in 9p21 were identified in 69% of tumors. Gains of 11q13 and 20q13 were mutually exclusive, and 1p13.2 gain was associated with 5p15.33. Our findings showed that alterations in RAS‐related pathways are present in 87.5% of acral lentiginous melanomas.     

Characterization and longitudinal monitoring of melanoma growth in ret‐transgenic mice using a single‐sequence MRI protocol

Spontaneous melanoma models in transgenic mice are increasingly used in preclinical research as they most closely match the progression of melanoma in humans. While optical inspection only allows analysis of tumors located on the skin, the accurate measurement and growth of subcutaneous tumors have not been adequately assessed. To improve the measurement accuracy of melanoma tumors, we used a fast single‐sequence MRI protocol at 9.4 Tesla for longitudinal characterization of a ret‐transgenic mouse model. Repeated MRI (average acquisition time 30 min per animal) of the trunk (excluding head and distal limbs) in six siblings revealed an increase in the mean total tumor volume (TTV) from 102.0 ± 80.5 mm³ at 35 days of age to 434.8 ± 154.9 mm³ by 77 days. The main tumor load was located within the pelvis (>40%), followed by the proximal hind limbs and groins (>30%). The smallest detectable tumor measured 0.07 mm³. Inter‐rater reliability between a radiologist and a veterinarian analysing MRI data was 0.993 for TTV and 0.840 for number of tumors (both p < 0.001). We thus conclude that because of the high variance of TTV of same‐aged mice, MRI should be used (i) to establish treatment groups matched for TTV and (ii) for longitudinal examination of the TTV in mice over the course of treatments.     

Diagnosis of an additional in situ melanoma does not influence survival for patients with a single invasive melanoma: A registry‐based follow‐up study

Using a large (N= 25 493) population‐based cohort from Queensland, Australia, we compared melanoma survival among cases with a single invasive melanoma only against those who also had a diagnosis of a single in situ melanoma. After adjustment for sex, age, body site, clinicopathological subtype, thickness and ulceration, it was found that there was no difference (P = 0.99) in 10‐year melanoma‐specific mortality following a diagnosis of an invasive lesion, whether or not an in situ melanoma was also present. We conclude that in situ melanomas do not alter the prognosis of an invasive melanoma.     

Impaired T‐cell‐dependent protection against Leishmania major infection in HIV‐positive patients is associated with worsened disease outcome

Cutaneous leishmaniasis (CL) patients coinfected with HIV are known to show a more severe, prolonged course of disease; the immunological basis is not known. We now assessed clinical features, sera and skin biopsies of HIV⁺ and HIV^? patients with CL to identify drivers of increased susceptibility to Leishmania. CL lesion numbers, surface, and healing duration were significantly increased in HIV⁺ as compared to HIV^? patients (2.5, 14 and >4‐fold, respectively). Patients with HIV infection exhibited lower serum Leishmania‐specific IgG levels and decreased IL‐6 and IL‐8. Most importantly, dramatically decreased numbers of CD4⁺ T cells (approximately eightfold), but not CD8⁺ cells, together with fewer CXCR3⁺ Th1 cells, fewer Foxp3⁺ effector/regulatory T cells, and reduced levels of IFN‐γ expression were found in lesional skin. Our findings suggest that compromised CD4⁺ T‐cell responses may be responsible for worsened disease outcome leading to defects in parasite elimination in the absence of sufficient numbers of IFN‐γ‐producing Th1 cells.     

BRAF,KIT and NRAS mutations and expression of c‐KIT,phosphorylated extracellular signal‐regulated kinase and phosphorylated AKT in Japanese melanoma patients

To clarify the status of gene mutation and activation of growth signal in melanoma of Japanese patients in vivo, we analyzed the mutation of BRAF exon 15, NRAS exon 2, and KIT exons 9, 11, 13, 17 and 18 in melanoma cells obtained by laser capture microdissection, and performed direct sequencing in 20 cases of acral lentiginous melanoma (ALM) and 17 cases of superficial spreading melanoma (SSM). In the study of the mutation of BRAF, pyrosequencing was also done. To examine the cell proliferation signaling, immunohistochemistry for phosphorylated extracellular signal‐regulated kinase (pERK), phosphorylated AKT (phosphorylated AKT) and c‐KIT was done. The mutation of BRAF p.V600E was detected in 13 cases of ALM (65.0%) and 12 cases of SSM (70.6%). No NRAS mutation was found in all cases. The mutation in exons 9, 11, and 18 of KIT was detected in nine cases. The mutation of BRAF and KIT showed no correlation with clinical stage, lymph node metastasis, tumor thickness, ulceration and histology. pERK and pAKT was observed in small population of melanoma cells and there was no correlation with gene mutation. Our results indicate that the mutations of BRAF and KIT exist in Japanese melanoma patients, however, the cell growth signaling may be regulated by not only these mutated genes, but by other unknown regulatory factors, which may affect the prognosis of melanoma.     

Disseminated CD8‐positive,CD30‐positive cutaneous lymphoproliferative eruption with overlapping features of mycosis fungoides and primary cutaneous anaplastic large cell lymphoma following remote solitary lesional presentation

CD8‐positive, CD30‐positive cutaneous lymphoproliferative disorders constitute a rare subset of T‐cell lymphoproliferative conditions, including variants of primary cutaneous anaplastic large cell lymphoma (ALCL), mycosis fungoides, lymphomatoid papulosis type D, cutaneous gamma‐delta T‐cell lymphoma and cutaneous peripheral T‐cell lymphoma. These entities share overlapping clinical, histopathologic and immunophenotypic features, presenting both a clinical and pathological diagnostic challenge. Presented here is a 73‐year‐old man with a disseminated, indolent CD30+, CD8+ cutaneous lymphoproliferative disorder with overlapping clinical and histopathological features of both mycosis fungoides and primary cutaneous ALCL, as well as features of lymphomatoid papulosis. To our knowledge, this is the first case of a generalized CD8+, CD30+ eruption with features of both mycosis fungoides and primary cutaneous ALCL arising following an episode of solitary primary cutaneous CD8‐positive ALCL.     

Distant metastasis due to heavily pigmented epithelioid melanoma with underlying BRAF V600E,NOTCH1, ERBB3, and PTEN mutations

Pigment‐synthesizing melanoma (PSM) describes a morphologically and genetically diverse group of melanomas. In contrast, pigmented epithelioid melanocytoma (PEM) encompasses a spectrum of indolent tumors now classified as borderline/intermediate melanocytic tumors. Herein, we report a case of widely metastatic heavily pigmented epithelioid melanoma with fatal outcome in a 36‐year‐old woman. Next‐generation sequencing identified somatic (tumoral) mutations in BRAF V600E, PTEN, NOTCH1, and ERBB3. By contrast, GNAQ and GNA11 were wild type. Prkar1α and p16 expression were maintained. Identification of mutations in NOTCH1 and ERBB3 may support the diagnosis of heavily pigmented epithelioid melanoma. In contrast, PRKCA fusion genes and PRKAR1A mutations support the diagnosis of PEM. Given the heterogeneity, potential overlap (loss of Prkar1α expression), and evolving genetic profiles of these two distinct groups of tumors, careful appraisal of molecular profiles in the light of histomorphology and clinical history is necessary for distinction between PEM and PSMs including heavily pigmented epithelioid melanomas, with significant potential impact on prognosis and therapy.     

Paeoniflorin suppresses vascular damage and the expression of E‐selectin and ICAM‐1 in a mouse model of cutaneous Arthus reaction

Paeoniflorin (PF) extracted from the root of Paeonia lactiflora pall, displays anti‐inflammation properties in several animal models. Adhesion molecules are important for the recruitment of leucocyte to the vessel wall and involved in the pathogenesis of various autoimmune and inflammatory diseases. Herein, we investigate the effects of PF on adhesion molecule expression in a mouse model of cutaneous Arthus reaction and cultured human dermal microvascular endothelial cells (HDMECs). We showed that PF significantly ameliorated the immune complex (IC) induced vascular damage, leucocyte infiltrates and adhesion molecules expression. Furthermore, PF markedly blocked tumor necrosis factor‐α (TNF‐α)‐induced E‐selectin and intercellular adhesion molecule‐1 (ICAM‐1) expression in HDMECs at both mRNA and protein levels. PF also suppressed TNF‐α‐induced adhesion of polymorphonuclear leucocytes (PMNs) to HDMECs. Finally, western blot data revealed that PF can inhibit the phosphorylation of p38, JNK in TNF‐α‐treated HDMECs. These data suggest that PF, as an anti‐inflammatory agent, can downregulate adhesion molecules expression. PF may be a candidate medicine for the treatment of IC‐induced inflammatory response.     

Index report of cutaneous angiosarcomas with strong positivity for tyrosinase mimicking melanoma with further evaluation of melanocytic markers in a large angiosarcoma series

Cutaneous angiosarcoma can be challenging to diagnose particularly when poorly vasoformative and studied on biopsies. We report a case of a cutaneous angiosarcoma with strong positivity for tyrosinase, the first to our knowledge, initially misdiagnosed as melanoma. We subsequently evaluated the reactivity of panmelanocytic cocktail (tyrosinase, HMB‐45 and Melan‐A), SOX10, tyrosinase and MITF in a large tissue microarray (TMA) of angiosarcoma. The TMA included 142 cases of angiosarcomas (29 cutaneous, 22 primary breast, 41 post‐radiation breast, 15 visceral, 26 deep soft tissue and bone, 5 chronic lymphedema‐associated and 4 angiosarcomas arising in other sarcomas). Immunohistochemical studies were performed with anti‐panmelanocytic cocktail, anti‐SOX10, anti‐MITF and anti‐tyrosinase antibodies. TMA staining results were scored on intensity and percentage of tumoral labeling. Aside from the index case, no cases (0 of 133) showed positivity for tyrosinase including 28 cutaneous angiosarcomas. One breast angiosarcoma (1 of 131) was positive for MITF. All cases were negative for SOX10 and panmelanocytic cocktail (0 of 132). Angiosarcomas can rarely be positive for tyrosinase and MITF. Pathologists should be cognizant of these rare exceptions to prevent confusion with melanoma. Additional immunohistochemical markers for vascular and melanocytic differentiation, thorough histological examination for vasoformative and in situ areas as well as clinical impression are helpful in these exceptionally problematic cases.     

BH3‐only proteins – possible proapoptotic triggers for melanoma therapy

Despite recent developments for new targeted therapies in melanoma, as BRAF inhibitors and immune‐stimulating antibodies, tumor relapse frequently follows within less than a year. Therapy resistance is explained by defects in proapoptotic signalling. Thus, efficient induction of apoptosis in tumor cells appears as predominant therapeutic goal. In apoptosis control of melanoma, the balance between pro‐ and antiapoptotic Bcl‐2 proteins plays a decisive role. In particular, members of the subfamily of BH3‐only proteins function as proapoptotic triggers, and mimetics of these proteins are already in clinical trials in other cancers. Recent experimental work has revealed that the effects of different treatments in melanoma are related to the activation of BH3‐only proteins, and also the proapoptotic effects of BRAF inhibitors are prevented by knockdown of the BH3‐only protein Bim. Thus, melanoma therapy might be critically improved by the combination of survival pathway antagonists as BRAF inhibitors with BH3 mimetics.     

Extracellular signal‐regulated kinase activation of self‐healing Langerhans cell histiocytosis: A case report

A 3‐month‐old boy developed small papules on his trunk. After the papules increased in number, the patient was diagnosed with Langerhans cell histiocytosis based on the pathological findings. He was referred to our department for further examination. Upon initial examination, the papules and nodules were scattered on his back, abdomen and lumbar region. Because he did not present with any organ involvement except the skin, he was diagnosed with single‐system and skin‐limited Langerhans cell histiocytosis. Skin rashes were treated with a topical steroid and started regressing 3 months after onset. All papules disappeared 6 months after onset. In this boy, the Langerhans cell histiocytosis tumor cells expressed phosphorylated extracellular signal‐regulated kinases. In Langerhans cell histiocytosis, BRAF V600E and other genes are known to mutate to act as driver mutations in stem cells of the myeloid dendritic cell lineage. Consequently, extracellular signal‐regulated kinases are continuously activated, which contributes to Langerhans cell histiocytosis carcinogenesis.     

Role of CPI‐17 in restoring skin homoeostasis in cutaneous field of cancerization: effects of topical application of a film‐forming medical device containing photolyase and UV filters

Cutaneous field of cancerization (CFC) is caused in part by the carcinogenic effect of the cyclobutane pyrimidine dimers CPD and 6‐4 photoproducts (6‐4PPs). Photoreactivation is carried out by photolyases which specifically recognize and repair both photoproducts. The study evaluates the molecular effects of topical application of a film‐forming medical device containing photolyase and UV filters on the precancerous field in AK from seven patients. Skin improvement after treatment was confirmed in all patients by histopathological and molecular assessment. A gene set analysis showed that skin recovery was associated with biological processes involved in tissue homoeostasis and cell maintenance. The CFC response was associated with over‐expression of the CPI‐17 gene, and a dependence on the initial expression level was observed (P = 0.001). Low CPI‐17 levels were directly associated with pro‐inflammatory genes such as TNF (P = 0.012) and IL‐1B (P = 0.07). Our results suggest a role for CPI‐17 in restoring skin homoeostasis in CFC lesions.     

Origin of Langerhans cells in normal skin and chronic GVHD after hematopoietic stem‐cell transplantation

Chronic graft‐versus‐host disease (cGVHD) is a common complication following allogeneic stem‐cell transplantation (SCT). Past studies have implicated the persistence of host antigen‐presenting cells (APCs) in GVHD. Our objective was to determine the frequency of host Langerhans cells (LCs) in normal skin post‐SCT and ask if their persistence could predict cGVHD. Biopsies of normal skin from 124 sex‐mismatched T‐cell‐replete allogenic SCT recipients were taken 100 days post‐transplant. Patients with acute GVHD and those with <9 months of follow‐up were excluded and prospective follow‐up information was collected from remaining 22 patients. CD1a staining and X and Y chromosome in‐situ hybridization were performed to label LCs and to identify their host or donor origin. At 3 months, 59 ± 5% of LCs were host derived. The density of LCs and the proportion of host‐derived LCs were similar between patients that did or did not develop cGVHD. Most LCs in the skin remained of host origin 3 months after SCT regardless of cGVHD status. This finding is in line with the redundant role of LCs in acute GVHD initiation uncovered in recent experimental models.