Quantitative comparison of MiTF, Melan-A, HMB-45 and Mel-5 in solar lentigines and melanoma in situ

Preferentially Expressed Antigen in Melanoma (PRAME) and Human Malignant Melanoma: A Retrospective Study

BACKGROUND

Preferentially expressed antigen in melanoma (PRAME) is a cancer testis antigen (CTA) identified in 1997 through analysis of the specificity of tumor-reactive T-cell clones derived from a patient with metastatic cutaneous melanoma. Although at first it seemed even more specific, various studies have shown that PRAME can also be expressed in the context of atypical lesions that do not correspond solely to the definition of malignant melanoma.

METHODS

A systematic review of English articles was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

126 records were identified in the literature search, of which 9 were duplicates. After screening for eligibility and inclusion criteria, 53 publications were included.

CONCLUSIONS

The advent of a new marker such as PRAME is surely a step forward not only in the diagnostic approach, but also in the immunotherapeutic approach to MM. However, various studies have shown that PRAME can also be expressed in the context of atypical lesions apart from MM and, for this reason, the diagnostic sensitivity and specificity (hence accuracy) are clearly lower. Further studies with larger case series will be necessary to understand better what possibilities are offered in terms of diagnostic reliability by PRAME.

Lichenoid dermatoses with pseudomelanocytic nests vs inflamed melanoma in situ: A comparative study

AIMS

Pseudomelanocytic nests or "pseudonests" arising in lichenoid dermatoses can be a diagnostic pitfall for melanoma in situ (MIS), especially on sun-damaged skin. We sought to evaluate histopathological features that may be helpful in distinguishing this benign process from inflamed MIS.

METHODS

Ten biopsy specimens containing pseudomelanocytic nests within lichenoid dermatoses and twenty cases of inflamed MIS were retrospectively reviewed. Cases with pseudomelanocytic nests represented either a rash (n = 6) or a discrete non-melanocytic lesion, such as lichenoid keratosis (n = 4).

RESULTS

All cases with pseudomelanocytic nests showed nests of microphthalmia-associated transcription factor-positive cells at the dermoepidermal junction (DEJ) with interface changes and lichenoid inflammation. Pagetoid scatter, confluence of solitary melanocytes at the DEJ and significant cytologic atypia was not seen in any of these cases. In contrast, all cases of inflamed MIS demonstrated confluence of single melanocytes at the DEJ with cytologic atypia (P < 0.001) and 18/20 cases showed pagetoid scatter of melanocytes (P = 0.001).

CONCLUSIONS

Our results show that, of the different histopathological features assessed, confluent growth and pagetoid scatter of atypical melanocytes were seen in most cases of inflamed MIS but were absent in all cases with pseudomelanocytic nests. Therefore, in addition to clinicopathological correlation, these features may be useful in differentiating pseudomelanocytic nests arising in lichenoid dermatoses from inflamed MIS.

Superficial dermal melanocytosis of the elderly: An exceptional occurrence?

The development of flat pigmented lesions on chronically sun-damaged (CSD) skin of the face may represent the clinical manifestation of a wide variety of hyperplastic/neoplastic melanocytic proliferations. We report the exceptional case of an acquired pigmented patch occurring on CSD skin, histopathologically characterized by diffuse hyperplasia of dendritic/spindled melanocytes in the superficial dermis within a widened band of actinic elastosis. This lesion was associated with a small focus of early invasive lentigo maligna melanoma (LMM). We show the melanocytic nature of the population of dermal pigmented cells by means of single and double immunohistochemical staining for melanocytic and histiocytic markers. The biologic significance of the focus of LMM within the hyperpigmented lesion (whether random collision phenomenon or causally related occurrence), as well as the pathogenesis of the whole dermal lesion are difficult to elucidate. Our case emphasizes the need for a better understanding of the pathophysiology of so-called dermal melanocytes.

Current perspectives on Mohs micrographic surgery for melanoma

Mohs micrographic surgery (MMS), a specialized surgical excision technique used primarily in the treatment of skin cancers, is tissue sparing and provides optimal margin control through evaluation of 100% of both the peripheral and deep margin. The use of MMS for the treatment of malignant melanoma (MM) and melanoma in situ (MIS) has been slow in gaining the same widespread acceptance that it has for keratinocyte carcinomas despite its cost-effectiveness and the growing body of evidence demonstrating similar or improved cure rates to standard wide local excision. However, modern advances in immunohistochemical staining have continued to greatly enhance the ability of Mohs surgeons to interpret MMS frozen sections of melanoma specimens – the primary concern of most opponents of MMS for melanoma. These advances, coupled with an increased recognition by professional organizations of the utility of MMS in treating MM and MIS, have led to a rise in the use of MMS for melanoma in recent years. Given the expanding role of MMS in the treatment of cutaneous melanoma, this manuscript will describe how MMS is performed, discuss the rationale and current evidence regarding the use of MMS for MM and MIS, review the immunohistochemical stains currently available for use in MMS, and consider special situations and future directions in this area of growing interest.

Lentigo maligna: diagnosis and treatment

Lentigo maligna (LM) is an in situ subtype of melanoma, clinically presenting as a pigmented, asymmetric macule that originates mostly on the head and neck and spreads slowly. The diagnosis may be challenging both for clinicians and pathologists. Dermatoscopy and reflectance confocal microscopy represent a useful tool in the differentiation of LM from other pigmented lesions, such as pigmented actinic keratosis, solar lentigines, seborrheic keratosis and lichen planus-like keratosis. Moreover, those non-invasive diagnostic technique may be crucial in the selection of optimal biopsy sites in equivocal lesions, in pre-surgical mapping and in evaluating and monitoring response to non-surgical treatments. Histologic examination remains the gold standard for the diagnosis of LM, showing a lentiginous proliferation of basal atypical melanocytes on a severe sun-damaged skin. The management of LM is constantly evolving. Treatments include surgery (the first choice, when available), radiotherapy and imiquimod cream (in patients not candidates to surgery). Many other possible treatments for LM have been tested, but they are not yet supported by strong evidences. We collected current guidelines and PubMed available reviews, studies and case-reports in order to make an overview on diagnosis and treatment of LM.

Atypical Melanocytic Proliferations: A Review of the Literature

BACKGROUND

Ambiguous histopathologic diagnoses represent a challenge for clinicians because of a lack of definitive diagnosis and related uncertainty about management.

OBJECTIVE

To review the literature on atypical melanocytic proliferations and detail synonymous terms, epidemiology, diagnostic work-up, histopathology, treatment, and prognosis.

METHODS

Databases from PubMed and Web of Science were searched for articles related to atypical melanocytic proliferations.

RESULTS

Intraepidermal melanocytic proliferations with features worrisome for possible melanoma in situ (MIS) are generally excised as for MIS. Reported rates of upstaging of such cases to invasive melanoma on review of the excision are very low. Because invasion, lymph node spread, and metastasis can occur in atypical melanocytic lesions with a thick intradermal component, these are often treated as for malignant melanoma.

CONCLUSION

Because the diagnosis dictates treatment, it is incumbent to establish a diagnosis as definitive as possible, obtaining second or third opinions and using ancillary studies when appropriate. When the diagnosis remains uncertain, it is difficult to provide guidelines for treatment. Clinical care decisions for patients with an uncertain diagnosis are best done on a case-by-case basis weighing probabilities of adverse outcomes against potential benefits and risks from various treatment options.

High intensity focused ultrasound enhances anti-tumor immunity by inhibiting the negative regulatory effect of miR-134 on CD86 in a murine melanoma model

HIFU has been demonstrated to enhance anti-tumor immunity, however, the mechanism of which has not been well elucidated. Emerging evidence indicates that miRNAs play important roles in immune response. In this study, we used the B16F10 melanoma allograft mouse model to investigate the role of miRNAs in HIFU-enhanced anti-tumor immunity. We found that HIFU treatment decreased circulating B16F10 cells and pulmonary metastasis nodules while increased IFN-γ and TNF-α in the peripheral blood and cumulative mouse survival, which was associated with inhibition of miR-134 expression and activation of CD86 expression in tumor tissues. Further, we determined that miR-134 directly binds to the 3′UTR of CD86 mRNA to suppress its expression in B16F10 cells. When B16F10 cells transfected with miR-134 were co-cultured with normal splenic lymphocytes, the secretion of IFN-γ and TNF-α from lymphocytes was reduced and B16F10 cell survival was increased. HIFU exposure efficiently decreased miR-134 while increased CD86 expression in B16F10 cells in vitro. CD86 knockdown with siRNA markedly rescued the viability of HIFU-treated B16F10 cells that co-cultured with lymphocytes. Altogether, our results suggest that HIFU down-regulates miR-134 to release the inhibition of miR-134 on CD86 in melanoma cells, thereby enhancing anti-tumor immune response.

Diagnosis and management of lentigo maligna: a review

Lentigo maligna is a melanocytic neoplasm occurring on sun-exposed skin, usually on the head and neck, of middle-aged and elderly patients. It is thought to represent the in situ phase of lentigo maligna melanoma. The ill-defined nature and potentially large size of lesions can pose significant diagnostic and treatment challenges. The goal of therapy is to cure the lesions in order to prevent development of invasive disease, and surgical excision is the treatment of choice to achieve clear histological margins. Nonsurgical treatment modalities have been reported; however, evidence is lacking to support their use. Age, general health, and comorbidities need to be taken into account when deciding the right treatment modality for each individual patient.

Emerging clinical applications of selected biomarkers in melanoma

Melanoma is a lethal skin disease with a mostly predictable clinical course according to a known constellation of clinical and pathologic features. The distinction of melanoma from benign melanocytic nevus is typically unequivocol; however, there is a subset of tumors known for its diagnostic challenges, development of late metastases, and difficulties in treatment. Several melanocytic tissue biomarkers are available that can facilitate the histopathologic interpretation of melanoma as well as provide insight into the biologic potential and mutational status of this disease. This review describes the clinical application of some of these established and emerging tissue biomarkers available to assess melanocytic differentiation, vascular invasion, mitotic capacity, and mutation status. The selected tissue biomarkers in this review include MiTF, Sox10, D2-40, PHH3, H3KT (anti-H3K79me3T80ph), anti-BRAFV600E, and anti-BAP-1.

Primary mucosal melanoma of the sinonasal tract: a clinicopathologic and immunohistochemical study of thirty-two cases

Sinonasal mucosal melanoma is a rare disease with poor survival. These tumors may have associated intraepithelial melanocytic proliferations, which are not extensively characterized. This retrospective analysis of 32 patients with sinonasal mucosal melanoma examined associated intraepithelial melanocytic proliferations in the context of diagnostic and prognostic features. Patient age ranged from 30 to 90 years (median 71) with a male to female ratio of approximately 3:2. Follow up for 31 patients ranged from 5 to 211 months (mean 42 months). Most patients died from melanoma-associated causes (18/31, 58 %), six (19 %) died from unknown causes, two (6 %) were alive with metastatic disease, and only five patients (16 %) remained alive without melanoma. The tumors were histopathologically heterogeneous, displaying epithelioid, spindled, and small cell cytomorphology. The presence of >2 mitoses/mm(2) and necrosis correlated with tumor progression and overall survival, respectively (p = 0.04 for both). Melanoma in situ, defined as a confluent intraepithelial proliferation of cytologically atypical melanocytes, was identified in 20 of 30 evaluable cases (67 %) and confirmed with immunohistochemical staining for microphthalmia-associated transcription factor. Melanocytic hyperplasia, defined as intraepithelial melanocytic proliferation without confluent growth or marked atypia, was seen in five cases (16 %). This incidence of associated intraepithelial melanocytic proliferations (83 %) is higher than previously reported. Because of the locally aggressive nature of these tumors, an awareness of the high rate of associated intraepithelial melanocytic proliferations may inform future studies of therapeutic options.

Investigation of cAMP microdomains as a path to novel cancer diagnostics

Understanding of cAMP signaling has greatly improved over the past decade. The advent of live cell imaging techniques and more specific pharmacologic modulators has led to an improved understanding of the intricacies by which cAMP is able to modulate such a wide variety of cellular pathways. It is now appreciated that cAMP is able to activate multiple effector proteins at distinct areas in the cell leading to the activation of very different downstream targets. The investigation of signaling proteins in cancer is a common route to the development of diagnostic tools, prognostic tools, and/or therapeutic targets, and in this review we highlight how investigation of cAMP signaling microdomains driven by the soluble adenylyl cyclase in different cancers has led to the development of a novel cancer biomarker. Antibodies directed against the soluble adenylyl cyclase (sAC) are highly specific markers for melanoma especially for lentigo maligna melanoma and are being described as "second generation" cancer diagnostics, which are diagnostics that determine the 'state' of a cell and not just identify the cell type. Due to the wide presence of cAMP signaling pathways in cancer, we predict that further investigation of both sAC and other cAMP microdomains will lead to additional cancer biomarkers. This article is part of a Special Issue entitled: The role of soluble adenylyl cyclase in health and disease.

MITF accurately highlights epidermal melanocytes in atypical intraepidermal melanocytic proliferations

Atypical intraepidermal melanocytic proliferations (AIMP) have random cytologic atypia and other histologic features that are concerning for malignancy and often require immunohistochemistry to differentiate from melanoma in situ. Immunostaining with S100, Melan-A, and microphthalmia-associated transcription factor (MITF) was performed for 49 morphologically well-characterized AIMP lesions. The percentage of cells in the basal layer of the epidermis that were identified as melanocytes by immunohistochemistry was compared with the percentage observed by morphology on hematoxylin and eosin staining, which is the gold standard stain for identifying cytologic atypia within an AIMP. Melan-A estimated the highest percentage of melanocytes and S100 the fewest in 47 of the 49 lesions examined. The estimated percentage of melanocytes was 23.3% (95% confidence interval: 18.6-28.1; P < 0.001) higher for Melan-A compared with hematoxylin and eosin staining. Melanocyte estimates were similar for hematoxylin and eosin and MITF (P = 0.15) although S100 estimated 21.8% (95% confidence interval: -27.2 to -16.4; P < 0.001) fewer melanocytes than hematoxylin and eosin. Melan-A staining produces higher estimates of epidermal melanocytes than S100 and MITF, which may increase the likelihood of diagnosing melanoma in situ. In contrast, melanoma in situ may be underdiagnosed with the use of S100, which results in lower estimates of melanocytes than the other 2 immunostains. Therefore, the best immunohistochemical marker for epidermal melanocytes is MITF.

Components in melanoma cytoplasm might induce murine BMSCs transformation and expression of Melan-A

This study explored the possibility that the components in melanoma cytoplasm induce murine BMSCs transformation and expression of Melan-A by morphologically observing the changes of BMSCs and immunocytochemically detecting Melan-A in the cells after culturing BMSCs in medium containing melanoma cytoplasm components (MCC). MCC of B16 melanoma cells was prepared and BMSCs were cultured and induced by adding the MCC into culture medium. The cells were morphologically observed and Melan-A was immunohistochemically detected to confirm BMSCs transformation. MCC-induced BMSCs underwent morphological changes. A number of melanin granules appeared in the cytoplasm of the cells and some were released into surrounding areas. Several cells that might come from one cell formed a cluster, and their granules, together with those secreted by other induced BMSCs, formed a so-called "sphere-formed structure". The induced BMSCs expressed Melan-A. We are led to conclude that there might be some factors in the cytoplasm of melanoma cells that might induce BMSCs transformation toward melanogenic cell, or even melanoma.