Cellular blue nevus tumor presenting as a submandibular lymph node in a 16-year-old.

The cellular blue nevus tumor is a type of dendritic melanocytic nevus that is typically benign and exceedingly rare. The incidence of all blue nevi is about 1%, usually affecting the adult population and appearing on the extremities, sacrococcygeal or gluteal regions. There have only been a handful of case reports cited in the literature where cellular blue nevi present in the head and neck region, usually affecting the scalp and young adult population (7, 8). As such, it is exceedingly rare to encounter a cellular blue nevus tumor in the neck or infiltrating into neck lymph nodes. Here we report a rare case of a cellular blue nevus tumor presenting as a right neck mass in a pediatric 16-year-old patient, shown to invade into the submandibular lymph node and surrounding soft tissue. It is important to be aware of the cellular blue nevus tumor as a differential diagnosis in pediatric neck masses. Histological evaluation is necessary to determine tumor aggression and malignant potential which can guide further treatment in pediatric patients.

Primary cutaneous perivascular epithelioid cell tumors: two cases and a review of the literature.

Report _Case Presentation _Photo Vignette _Letter Authors declare that the contents of this article are their own original unpublished findings. Title: Primary cutaneous perivascular epithelioid cell tumors: two cases and a review of the literature Authors: Jennifer Wong1 DO, Jason Mammino2 DO, Jennifer Seyffert3 DO, Kristen Schmits4 MD, Etan Marks4 MD, Daniel Rivlin3 MD Affiliations: 1Department of Dermatology, LECOM- Larkin Community Hospital, Miami, Florida, USA, 2Department of Dermatology, KCUMB - Advanced Dermatology and Cosmetic Surgery, Orlando, Florida, USA, 3Department of Dermatology, LECOM- Skin and Cancer Associates, Miami Beach, Florida, USA, 4Department of Dermatopathology Advanced Dermatology and Cosmetic Surgery Pathology Laboratory, Delray Beach, Florida, USA Corresponding Author: Jennifer Seyffert DO, 4308 Alton Road, Suite 510, Miami Beach, FL 33140, Tel: 305-674-8865, Fax: 305-674-1459, Email: jseyf12@gmail.com Abstract: Perivascular epithelioid cell tumors, also known as PEComas, are mesenchymal neoplasms which uncommonly originate within the skin, with only 23 cases documented within the literature. These rare neoplasms classically display epithelioid cells composed of granular or clear cytoplasm arranged in sheets, nests, or cords. Their immunoreactivity for melanocytic and smooth muscle markers makes these tumors distinct and unique.[1] We herein present two cases of primary cutaneous PEComas that clinically mimic other common cutaneous neoplasms and illustrate the necessity for clinical-pathologic correlation. A literature review is also presented to compare the different clinical and histological presentations of cutaneous PEComas.

Melanosome transfer evaluation by quantitative measurement of Pmel 17 in human normal melanocyte-keratinocyte co-cultures: effect of an Alaria esculenta extract.

Numerous strategies have been proposed to evaluate melanosome transfer. Methods allowing quantitative measurements of this transfer in human normal cellular models, however, are very few and often require extremely specialized devices that are expensive and difficult to use. As a part of the melanosome-specific membrane-bound glycoprotein, Pmel 17 is released from the melanosome membrane by ectodomain shedding. We reasoned, therefore, that it should be possible to evaluate melanosome transfer by quantifying this "soluble" Pmel 17. The Pmel 17 ELISA assay developed permits a detection of 10 to 1000 ng/ml of this glycoprotein in human normal melanocyte-keratinocyte co-culture media. As expected, niacinamide, a well-known melanosome transfer inhibitor, significantly reduced the Pmel 17 quantities found in the culture media. This validated our experimental design. We then used our model to show that a whitening cosmetic active compound, i.e., an Alaria esculenta extract, can (at least in part) enable a significant decrease in the melanosome transfer to produce a lightening effect without affecting melanin production. This research provides a simple and efficient method to quantify melanosome transfer in a human normal co-culture model. It is a particularly useful tool with which to facilitate the development of new active whitening compounds.

Ipilimumab. Immunostimulant; more assessment needed.

In patients with inoperable or metastatic melanoma, first-line cytotoxic drugs have no proven impact on survival, which is generally limited to only a few months. There is no standard second-line treatment. Ipilimumab, a monoclonal antibody, stimulates T lymphocyte proliferation and activation. It has been authorised in the European Union for melanoma patients in whom one or more lines of chemotherapy have failed. Clinical evaluation is based on a double-blind randomised trial in 676 patients comparing ipilimumab + gp 100, ipilimumab + placebo, and 100 gp + placebo. Gp 100 is an experimental mixture of proteins being tested in melanoma. The median overall survival time was significantly longer among patients treated with ipilimumab, with or without gp 100 (about 10 months), than among those receiving gp 100 + placebo (about 6 months). In another trial, involving previously untreated melanoma patients, adding ipilimumab (at a dose 3 times higher than in the previous trial) to dacarbazine prolonged median overall survival by 2 months. The main adverse effects of ipilimumab are immune-related adverse reactions, and include gastrointestinal, cutaneous and endocrine disorders (enterocolitis with or without perforation, dermatitis, hypopituitarism and hepatitis). In practice, in patients with metastatic melanoma in whom one or more treatments have failed, the use of ipilimumab should be restricted to well-designed clinical trials designed to better assess the survival benefit, serious adverse effects, and the optimal dosage.

Flow cytometry assessment of residual melanoma cells in tumor-infiltrating lymphocyte cultures.

Adoptive transfer of tumor-infiltrating lymphocytes (TIL) is in development for the treatment of metastatic melanoma. In phase II clinical trials, patients with metastatic melanoma that received TIL after preconditioning had a 50-70% clinical response rate. The current approach to generate TIL is to culture melanoma enzyme digests in the presence of IL-2 for a 10- to 20-day period followed by 2 weeks of rapid expansion (REP). Prior to administration, cell therapies are characterized and tested for purity. TIL are characterized by CD3 surface marker expression, and purity is assessed by the amount of tumor remaining in culture. Evaluating TIL purity has traditionally been done by immunohistochemistry, which is often considered semiquantitative. To generate a quantitative assay, we used multiparameter flow cytometry to evaluate the presence of viable tumor cells by staining TIL populations with a viability dye and an antibody cocktail that detects intracellular tumor-antigens gp100, Mart-1, tyrosinase, S100, and surface tumor-antigen melanoma chondroitin sulfate proteoglycan (MCSP), and CD3 on T cells. Tumors were identified by gating on the viable CD3(-) population. Antigens in tumors were initially optimized with individual antibodies using both immunohistochemistry and flow cytometry. When eight different tumor cell lines were spiked into an activated T cell culture, flow cytometry was able to distinguish lymphocytes from tumors in all samples tested. Most importantly, the assay was able to detect melanoma cells in all enzyme digests (9/9) from patient samples. After IL-2-induced TIL expansion, there was a significant decrease in tumor cells; tumor cells were detected in only 2 of 12 samples. In eight IL-2-induced TIL samples that were further expanded in REP, no tumor cells were detected. We have demonstrated that flow cytometry is an alternative to immunohistochemistry for defining the purity of a TIL population.

A mouse model of vitiligo with focused epidermal depigmentation requires IFN-γ for autoreactive CD8⁺ T-cell accumulation in the skin.

Vitiligo is an autoimmune disease of the skin causing disfiguring patchy depigmentation of the epidermis and, less commonly, hair. Therapeutic options for vitiligo are limited, reflecting in part limited knowledge of disease pathogenesis. Existing mouse models of vitiligo consist of hair depigmentation but lack prominent epidermal involvement, which is the hallmark of human disease. They are thus unable to provide a platform to fully investigate disease mechanisms and treatment. CD8(+) T cells have been implicated in the pathogenesis of vitiligo, and expression of IFN-γ is increased in the lesional skin of patients, however, it is currently unknown what role IFN-γ has in disease. Here, we have developed an adoptive transfer mouse model of vitiligo using melanocyte-specific CD8(+) T cells, which recapitulates the human condition by inducing epidermal depigmentation while sparing the hair. Like active lesions in human vitiligo, histology of depigmenting skin reveals a patchy mononuclear infiltrate and single-cell infiltration of the epidermis. Depigmentation is accompanied by accumulation of autoreactive CD8(+) T cells in the skin, quantifiable loss of tyrosinase transcript, and local IFN-γ production. Neutralization of IFN-γ with antibody prevents CD8(+) T-cell accumulation and depigmentation, suggesting a therapeutic potential for this approach.

In vivo vitiligo induction and therapy model: double-blind, randomized clinical trial.

In this study, we developed an in vivo vitiligo induction model to explore the underlying mechanisms leading to Koebner's phenomenon and to evaluate the efficacy of therapeutic strategies. The model consisted of 12 pigmented test regions on the back of generalized vitiligo patients that were exposed to three Koebner induction methods: cryotherapy, 755 nm laser therapy, and epidermal abrasion. In addition, four cream treatments (pimecrolimus, tacrolimus, steroid and placebo) were randomly applied. Koebnerization was efficiently induced by all three induction methods. In general, cryotherapy was the best method of Koebner induction, followed by 755 nm laser therapy and epidermal abrasion. Reproducible results were obtained, which showed enhanced depigmented surface areas and higher amounts of T lymphocytes in placebo-treated test zones compared to active treated areas. Tacrolimus and local steroids were better inhibitors of Koebner's process (P < 0.05) compared to pimecrolimus. Our in vivo vitiligo induction model is very informative to investigate vitiligo induction and to determine the efficacy of topical treatments in vitiligo. This proof of concept confirms the efficient comparison of head-to-head therapeutic strategies intra-individually in a standardized, specific and better timed way.

MART-1- and gp100-expressing and -non-expressing melanoma cells are equally proliferative in tumors and clonogenic in vitro.

MART-1 and gp100 are prototypical melanoma antigen (Ag), but their clinical use as vaccines or as targets of cytotoxic lymphocytes achieved modest success. Possible explanations could be that as MART-1 and gp100 are melanocyte differentiation Ag, clonogenic Ag-non-expressing cells would be spared by immune effectors, or that clonogenic cells would be intrinsically resistant to cytotoxic lymphocytes. We therefore analyzed the proliferative status of MART-1/gp100-expressing and -non-expressing cells in biopsies, and the clonogenicity and sensitiveness to cytotoxic lymphocytes of the human cutaneous melanoma cell lines MEL-XY1 and MEL-XY3. Analysis of MART-1/gp100 and Ki-67 expression in 22 melanoma tumors revealed that MART-1/gp100-expressing and -non-expressing cells proliferated competitively. MART-1, gp100, tyrosinase, and CD271 expression were studied in MEL-XY1 and MEL-XY3 colonies. At 7 days, colonies displayed positive, negative, and mixed expression patterns. By 14 days, colonies of different sizes developed, showing cells with different clonogenic potential, and Ag were downregulated, suggesting Ag plasticity. Subcloning of MEL-XY1 colonies showed that Ag expression varied with time without interfering with clonogenicity. Finally, clonogenic, MART-1/gp100-expressing cells were lysed by specific CD8 lymphocytes. Thus, MART-1 and gp100 expression and plasticity would not interfere with proliferation or clonogenicity, and clonogenic cells may be lysed by cytotoxic lymphocytes.

Pediatric "STUMP" lesions: evaluation and management of difficult atypical Spitzoid lesions in children.

Spitz nevi represent a distinct type of melanocytic nevi more commonly seen in childhood. Although typically benign, a subset of Spitz lesions raise concern and create a diagnostic dilemma as a result of confusing histology that involves characteristics of classic Spitz nevi intermixed with features of cutaneous melanoma. Such atypical Spitz lesions, or Spitzoid tumors of uncertain malignant potential, are difficult to classify and their biologic potential is uncertain. Nonetheless, these are critical tasks for both prognosis and clinical management. New tools, such as immunohistochemical stains, comparative genomic hybridization, and fluorescence in situ hybridization, have been used to provide further insight into these controversial lesions and to aid in their evaluation. In this review, we present our experience managing 6 cases of Spitzoid tumor of uncertain malignant potential and discuss the potential use of various diagnostic modalities, including sentinel lymph node biopsy, immunostaining, and molecular analysis.

Prediction of recurrence using exfoliative cytology and melanoma-associated antigen-A mRNA analysis following wide excision of oral squamous cell carcinoma: short report.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is the sixth most common cancer. The local recurrence of OSSC might result from the existence of occult cancer cells around tumour margins. Exfoliative cytology has lately gained great importance as a method for obtaining RNA samples from suspicious oral mucosal lesions in order to carry out molecular diagnosis. In addition, melanoma associated-A antigens (MAGE-A) are expressed in various tumours and their detection is a highly accurate sign that cancer cells are present. OBJECTIVE: The prediction of a recurrence using MAGE-A mRNA expression analysis to follow-up OSCC cases using a newly established molecular diagnostic technique applied to cytological materials. METHODS: RNA was extracted from three recurrent OSCC cases and from 20 healthy volunteers as a control group using a cytobrush. The expression of MAGE-A3, A4, A6, A10 and A12 was investigated in these specimens using quantitative real-time (RT-PCR). RESULTS: There was no expression of MAGE-A in the specimens of normal oral mucosa. However, the expression analysis of five different MAGE-A genes indicated a high potential for malignant change in biopsy-proven recurrent OSCC cases. Except for MAGE-A10, the rest of the genes were expressed in different ratios by the three recurrent cases, which had been determined on histopathology to be OSCC or carcinoma in situ. CONCLUSION: It is suggested that analysis of MAGE-A expression may be used as a risk prediction method in the diagnosis of recurrence after wide excision of OSCC to enhance the accuracy of exfoliative cytology, which has limitations due to false negative and false positive results.