Dermoscopic criteria associated with BRAF and NRAS mutation status in primary cutaneous melanoma.

BACKGROUND: The identification of BRAF mutations in melanoma led to the development and implementation of new and effective therapies. Few clinical and histological features have been associated with this mutational status. OBJECTIVES: The main objective of this study was to investigate clinical, histopathological and dermoscopic characteristics of primary melanomas according to BRAF or NRAS mutational status. METHODS: An observational retrospective study including melanoma dermoscopy images assessed for somatic mutations in BRAF and NRAS. RESULTS: Seventy-two patients were included, 30 women (42%) and 42 men (58%), mean age was 59 ± 15.51 years. BRAF-mutated melanomas were more frequently located on the trunk (n = 18, 64% for BRAF-mutated vs. n = 11, 29% for wild-type melanomas, P = 0.013). Histological ulceration was associated with the presence of BRAF mutations [odds ratio (OR) 3.141; 95% confidence interval (CI) 1.289-7.655; P = 0.002]. The Breslow index tended to be thicker in BRAF-mutated compared with wild-type (P = 0.086). BRAF mutations were present in 28 (39%) patients and only four cases were positive for NRAS mutations (6%), BRAF and NRAS mutations being mutually exclusive. The presence of dermoscopic peppering was associated with MAPK mutations (BRAF and NRAS) (OR 1.68; 95% CI 1.089-2.581; P = 0.015). Dermoscopic ulceration was also associated with BRAF mutations excluding acral and facial melanomas (OR 2.64; 95% CI 1.032-6.754). CONCLUSIONS: This study showed a correlation between BRAF and NRAS status and dermoscopic findings of 'peppering' as an expression of regression and melanophages in the dermis, suggesting a morphological consequence of immune behaviour in BRAF-mutated melanomas.

Dermoscopy of acral melanoma: a multicenter study on behalf of the international dermoscopy society.

BACKGROUND: Most studies on dermoscopy of acral lesions were conducted in Asian populations. In this study, we analyzed these features in a predominantly Caucasian population. OBJECTIVE: Estimate the prevalence of dermoscopic features in acral lesions, and assess their level of agreement between observers. METHODS: In this retrospective multicenter study, 167 acral lesions (66 melanomas) were evaluated for 13 dermoscopic patterns by 26 physicians, via a secured Internet platform. RESULTS: Parallel furrow pattern, bizarre pattern, and diffuse pigmentation with variable shades of brown had the highest prevalence. The agreement for lesion patterns between physicians was variable. Agreement was dependent on the level of diagnostic difficulty. CONCLUSION: Lesions with a diameter >1 cm were more likely to be melanoma. We found as well that a benign pattern can be seen in parts of melanomas. For this reason one should evaluate an acral lesion for the presence of malignant patterns first.

Dermoscopy of scalp tumours: a multi-centre study conducted by the international dermoscopy society.

BACKGROUND: Little is known about the dermoscopic features of scalp tumours. Objective To determine the dermoscopic features of scalp tumours. METHODS: Retrospective analysis of dermoscopic images of histopathologically diagnosed scalp tumours from International Dermoscopy Society members. RESULTS: A total of 323 tumours of the scalp from 315 patients (mean age: 52 years; range 3-88 years) were analysed. Scalp nevi were significantly associated with young age (<30 years) and exhibited a globular or network pattern with central or perifollicular hypopigmentation. Melanoma and non-melanoma skin cancer were associated with male gender, androgenetic alopecia, age >65 years and sun damage. Atypical network and regression were predictive for thin (≤1 mm) melanomas, whereas advanced melanomas (tumour thickness > 1 mm) revealed blue white veil, unspecific patterns and irregular black blotches or dots. CONCLUSIONS: The data collected provide a new knowledge regarding the clinical and dermoscopy features of pigmented scalp tumours.

Activation of Notch1 signaling in stromal fibroblasts inhibits melanoma growth by upregulating WISP-1.

The tumor microenvironment is emerging as an important target for cancer therapy. Fibroblasts (Fbs) within the tumor stroma are critically involved in promoting tumor growth and angiogenesis through secretion of soluble factors, synthesis of extracellular matrix and direct cell-cell interaction. In this work, we aim to alter the biological activity of stromal Fbs by modulating the Notch1 signaling pathway. We show that Fbs engineered to constitutively activate the Notch1 pathway significantly inhibit melanoma growth and tumor angiogenesis. We determine that the inhibitory effect of 'Notch-engineered' Fbs is mediated by increased secretion of Wnt-induced secreted protein-1 (WISP-1) as the effects of Notch1 activation in Fbs are reversed by shRNA-mediated blockade of WISP-1. When 'Notch-engineered' Fbs are co-grafted with melanoma cells in SCID mice, shRNA-mediated blockade of WISP-1 reverses the tumor-suppressive phenotype of the 'Notch-engineered' Fbs, significantly increases melanoma growth and tumor angiogenesis. Consistent with these findings, supplement of recombinant WISP-1 protein inhibits melanoma cell growth in vitro. In addition, WISP-1 is modestly expressed in melanoma-activated Fbs but highly expressed in inactivated Fbs. Evaluation of human melanoma skin biopsies indicates that expression of WISP-1 is significantly lower in melanoma nests and surrounding areas filled with infiltrated immune cells than in the adjacent dermis unaffected by the melanoma. Overall, our study shows that constitutive activation of the Notch1 pathway confers Fbs with a suppressive phenotype to melanoma growth, partially through WISP-1. Thus, targeting tumor stromal Fbs by activating Notch signaling and/or increasing WISP-1 may represent a novel therapeutic approach to combat melanoma.

Difficult early melanomas.

There is a spectrum of melanocytic tumors from benign to malignant. The goal of the dermatologist is to identify and remove early melanomas because doing so can be lifesaving. At the same time, it is inappropriate to randomly remove benign nevi. Dermatoscopy is an additional tool that can be used to help discriminate features that may assist in the diagnosis of melanoma. Even with dermatoscopy, identification of an early melanoma can be difficult. It is important to consider all clinical information available when making a management decision.

Identification of higher risk thin melanomas should be based on Breslow depth not Clark level IV.

BACKGROUND: There is good prognostic correlation for the two microstaging systems, Breslow depth and Clark level, commonly used to stage melanomas. Many investigators have reported that Breslow depth is the superior microstaging method. Although Clark level has been dropped from most of the proposed American Joint Committee on Cancer (AJCC) melanoma staging system, the AJCC system still includes Clark Level IV as a criterion for upstaging thin melanomas. The authors sought to determine whether this is appropriate, based on melanoma patient data in the Duke Comprehensive Cancer Center database. METHODS: Of the 8833 patients registered between January 1, 1970 and December 31, 1995, complete data on Breslow depth and Clark level was available for 4560 patients who were without nodal or metastatic disease at presentation. Ten-year survival was measured from the date of excision of the primary tumor until death from melanoma and analyzed using Kaplan-Meier and Cox proportional hazard methodologies. RESULTS: When analyzed separately, both increased Breslow thickness and Clark level correlated with shorter survival times. During subgroup analysis, Breslow thickness remained a significant prognostic indicator of survival at Clark Levels III and IV. Conversely, at narrow levels of Breslow thickness (i.e., 0-0.75 mm, > 0.75 -1.0 mm, > 1.0-1.5 mm) survival times were indistinguishable between Clark Levels III and IV. For the broader Breslow thickness interval of 0-1.0 mm, a barely significant difference between Clark Levels III and IV could be obtained. However, for this thickness range, even greater differences in survival could be obtained by merely comparing Breslow subgroups (i.e., < or = 0.8 mm vs. > 0.8-1.0 mm, < or = 0.9 mm vs. > 0.9-1.0 mm). CONCLUSION: The authors' data suggested that, after controlling for Breslow depth, Clark level was not a good prognostic indicator for survival. If the AJCC's objective is to design a classification system that will reliably predict the higher risk melanomas, then the system should be based on tumor thickness, which is clearly a better prognostic indicator, and should not be modified because of Clark level.

Malignant melanoma with paradoxical maturation.

Typically, melanocytic nevi "mature" (i.e., exhibit a morphologic shift to smaller or spindle cells with progressive depth in the dermis). In contrast, most malignant melanomas (conventional MMs) lack maturation, and are composed of large pleomorphic cells throughout. The authors describe a series of melanomas with paradoxical maturation mimicking the pattern of nevi. Seventeen primary invasive melanomas with paradoxical maturation (IMPs), two epidermotropic metastatic melanomas with maturation (EMMMs), 13 compound nevi (CN), and 14 conventional MMs without apparent maturation were analyzed by histologic, cytomorphometric, and immunohistochemical techniques. With increasing dermal depth, both CN and IMPs had smaller nuclear and cellular areas, and decreased expression of Ki-67, glycoprotein (gp)100 (with HMB-45), and tyrosinase. IMPs had significant differences from conventional MMs; namely, smaller nuclear and cytoplasmic areas (deep), and decreased expression of Ki-67 (superficial and deep), gp100 (deep), and tyrosinase (deep). IMPs also had notable differences from CN: namely, larger nuclear and cellular areas, more confluence, more mitotic figures, increased Ki-67 and gp100 expression in both the superficial and deep portions, and more melanin (deep). The two EMMMs exhibited histologic and immunohistochemical features similar to the primary IMPs. IMP, because of its mimicry of nevus, can present a diagnostic hazard. The authors propose histologic, morphometric, and immunohistochemical criteria that facilitate recognition and accurate diagnosis of this unusual variant of melanoma.

Reliability and accuracy of dermatologists' clinic-based and digital image consultations.

BACKGROUND: Telemedicine technology holds great promise for dermatologic health care delivery. However, the clinical outcomes of digital image consultations (teledermatology) must be compared with traditional clinic-based consultations. OBJECTIVE: Our purpose was to assess and compare the reliability and accuracy of dermatologists' diagnoses and management recommendations for clinic-based and digital image consultations. METHODS: One hundred sixty-eight lesions found among 129 patients were independently examined by 2 clinic-based dermatologists and 3 different digital image dermatologist consultants. The reliability and accuracy of the examiners' diagnoses and the reliability of their management recommendations were compared. RESULTS: Proportion agreement among clinic-based examiners for their single most likely diagnosis was 0. 54 (95% confidence interval [CI], 0.46-0.61) and was 0.92 (95% CI, 0. 88-0.96) when ratings included differential diagnoses. Digital image consultants provided diagnoses that were comparably reliable to the clinic-based examiners. Agreement on management recommendations was variable. Digital image and clinic-based consultants displayed similar diagnostic accuracy. CONCLUSION: Digital image consultations result in reliable and accurate diagnostic outcomes when compared with traditional clinic-based consultations.

Numbers and differentiation status of melanocytes in idiopathic guttate hypomelanosis.

The etiology and pathogenesis of idiopathic guttate hypomelanosis (IGH) are largely unknown. To investigate whether the pathologic alteration in IGH involves changes in melanocytic differentiation, cell number, or both, we studied nine lesions of IGH by immunoperoxidase, using monoclonal antibodies against the KIT receptor and a panel of melanocyte differentiation antigens (tyrosinase-related protein-1, tyrosinase, and gp100/pme117). In each case, compared with grossly normal non-lesional skin, IGH lesions showed markedly reduced numbers both of KIT+ cells and of cells expressing melanocyte differentiation antigens (p < 0.0001). Double immunofluorescence labeling of lesions revealed only scattered cells with a less-differentiated phenotype, i.e. cells positive for KIT but having low or undetectable TRP-1. These results indicate that the pathogenesis of IGH involves an absolute decrease in the number of melanocytes; a block in melanocyte differentiation does not appear to be a major component of the process.

A pilot trial of digital imaging in skin cancer.

We have used inexpensive off-the-shelf equipment for store-and-forward teledermatology and compared the precision and accuracy of digital image consultations with conventional, clinic-based consultations. Thirteen lesions were studied on 12 patients referred to a dermatology clinic for a suspected skin cancer. Patients were examined by two dermatologists. Subsequently, digital images were examined by two different dermatologists. There was almost complete agreement, both among and between the clinical and digital examiners, on different diagnosis and biopsy recommendations. Agreement on the single most likely diagnosis was also good. Digital imaging shows promise in teledermatology.

The SCF/KIT pathway plays a critical role in the control of normal human melanocyte homeostasis.

During development, the interaction of stem cell factor (SCF) with its receptor, KIT, is critical for the survival of melanocytes. Limited in vivo human studies have suggested a possible activating role of SCF on adult human melanocytes. In order to study the impact of this pathway on normal melanocyte homeostasis, human skin xenografts were treated with serial injections of recombinant human SCF or a KIT-inhibitory antibody (K44.2). On histologic evaluation, SCF injection increased, whereas KIT inhibition decreased the number, size, and dendricity of melanocytes. Immunohistochemical expression of melanocyte differentiation antigens, including tyrosinase-related-protein-1 and gp100/pmel17, was markedly increased by treatment with SCF, and decreased by K44.2 treatment. The number of Ki67-positive melanocytes was increased in the SCF-treated tissue, suggesting a direct proliferative effect of SCF; conversely, treatment with K44.2 resulted in melanocyte loss, which did not appear reversible with prolonged treatment. These findings demonstrate that the SCF/KIT pathway remains critical in adult human skin, and that pharmacologic modulation of this single pathway can control cutaneous melanocyte homeostasis.

Follicular mucinosis as a presenting sign of acute myeloblastic leukemia.

Follicular mucinosis is often associated with mycosis fungoides and has been rarely observed to occur with other neoplastic and inflammatory conditions. We describe a 60-year-old patient with follicular mucinosis who later developed acute myelogenous leukemia. This is the first reported case of follicular mucinosis as a presenting sign of acute myeloblastic leukemia in the absence of mycosis fungoides or leukemia cutis.

The rational clinical examination. Does this patient have a mole or a melanoma?

Lifetime risk for malignant melanoma has increased from 1 in 1500 in the United States in 1930 to 1 in 75 projected for the year 2000. Because the tumor's thickness at excision is the primary prognostic determinant, early detection through the history and physical examination can play an important role in the patient's clinical course. Two checklists have been developed as diagnostic aids, the ABCD (A indicates asymmetry; B, border irregularity; C, irregular color; and D, diameter >6 mm) and the revised 7-point checklists. These checklists should be interpreted with some discretion, but 2 studies have found the sensitivity for the ABCD checklist to be 92% (95% confidence interval [CI], 82%-96%) and 100% (95% CI, 54%-100%); 1 study found the specificity to be 98% (95% CI, 95%-99%). The revised 7-point checklist has been reported to have a sensitivity of 79% (95% CI, 70%-85%) to 100% (95% CI, 94%-100%) and specificity of 30% (95% CI, 21%-39%) to 37% (95% CI, 28%-46%). Physicians' global assessments for detecting the presence or absence of melanoma are estimated to have a specificity of 96% to 99%, while sensitivity ranges widely from 50% to 97%. Nondermatologists' examinations appear to be less sensitive than examinations performed by dermatologists.

KIT expression reveals a population of precursor melanocytes in human skin.

Human skin is believed to harbor a reservoir population of precursor melanocytes. It has been difficult to identify these putative cells experimentally, because they lack phenotypic features that define mature melanocytes. We have evaluated expression of the KIT tyrosine kinase receptor, which is critical for melanocyte development, as a possible marker of these cells. Sections of human skin were evaluated with single- and double-immunolabeling techniques. KIT-reactive dendritic cells were identified in the basal layer of the epithelia and were most numerous in the follicular infundibula and the rete ridges. These cells were located on the epithelial side of the basement membrane and lacked expression of cytokeratin and mast cell tryptase. The location of the KIT-reactive cells was distinctly different from that of Langerhans cells (identified with anti-CD1a) or Merkel cells (identified with CAM 5.2). Within the epidermis and upper follicular infundibulum the majority of the KIT-reactive dendritic cells also coexpressed TRP-1, a marker present in differentiated melanocytes. In the deeper follicular regions, the coexpression of TRP-1 in the KIT-reactive cells was absent. Throughout the epidermis and follicle, however, the KIT-reactive cells coexpressed BCL-2, a marker known to be increased in melanocytes. Thus, KIT expression reveals a population of intraepithelial cells that have immunophenotypic characteristics of mature melanocytes within the upper epithelial regions, but lack the differentiated melanocytic phenotype within the deeper follicular regions. We propose that these KIT(+), BCL-2(+), and TRP-1(-) cells constitute a precursor melanocyte reservoir of human skin.

Human recombinant stem-cell factor induces melanocytic hyperplasia in susceptible patients.

BACKGROUND: Recombinant human stem-cell factor (SCF), a cytokine acting on hematopoietic progenitor cells, has potential for the treatment of several hematologic and oncologic disorders. In a hematology-oncology phase I trial of SCF, several patients had cutaneous hyperpigmentation at the SCF subcutaneous injection sites. OBJECTIVE: Our purpose was to investigate the pathogenesis of this hyperpigmentation phenomenon. METHODS: Skin biopsy specimens were obtained before, at the completion of, and after SCF therapy and were processed for histology, immunohistology, and electron microscopy. RESULTS: Skin at the site of SCF injection had an increased number of melanocytes, increased melanocytic dendrite extension, and melanin as compared with noninjected tissue. Immunohistochemical stains revealed an increase in staining with melanocyte-specific monoclonal antibodies HMB-45 and NKI/beteb, and a monoclonal antibody to the receptor for SCF, c-kit. CONCLUSION: Subcutaneous injection of SCF results in hyperplasia of melanocytes. SCF may be useful in the treatment of melanocytopenic disorders, but caution may be necessary in patients with disorders of melanocyte proliferation.

Ber-EP4 immunoreactivity in normal skin and cutaneous neoplasms.

Ber-EP4 is an antibody raised against a cell membrane glycoprotein of, as yet, unknown function. In the skin, the ability to distinguish basal cell carcinoma from squamous cell carcinoma has been emphasized. Immunoreactivity in apocrine and eccrine secretory coil epithelium, Merkel cell carcinoma, and cutaneous mixed tumor has been reported. Having observed more widespread staining than previously reported, we sought to characterize further Ber-EP4 immunoreactivity by examining 76 formalin-fixed and paraffin-embedded proliferative epithelial skin lesions, 2 sections of fetal skin with developing adnexa, and frozen sections of skin from Mohs surgery procedures, using hematoxylin and eosin and Ber-EP4 immunostaining. In paraffin-embedded skin, matrical and outer sheath epithelium of vellus anagen follicles, inferior segment epithelium of vellus telogen follicles, and secretory coils of sweat glands stain with Ber-EP4, but anagen terminal follicle epithelium and eccrine and apocrine sweat ducts are negative. On frozen section, additional staining of eccrine ducts and cells in the outer sheath and matrix of the inferior segment of terminal follicles is noted. Basaloid epithelium of trichoepitheliomas, follicular induction over dermatofibromas, mammary Paget's disease, and selected other neoplasms showing eccrine or apocrine differentiation stain with Ber-EP4. These data indicate that in addition to basal cell carcinoma, Ber-EP4 staining may be seen in a variety of proliferative epidermal and adnexal lesions.

Immunohistochemical techniques in Mohs micrographic surgery: their potential use in the detection of neoplastic cells masked by inflammation.

BACKGROUND: Histopathologic evaluation of tissue obtained from Mohs micrographic surgery is the key step in obtaining complete tumor removal. Residual undetected tumor may result in recurrence. OBJECTIVE: In circumstances in which the histopathologic interpretation is difficult, we assessed the potential use of immunohistochemical techniques to detect tumor in Mohs micrographic surgical specimens. METHODS: A rapid immunoperoxidase technique with monoclonal anticytokeratin antibodies was performed on Mohs frozen sections. Cases selected included morpheaform basal cell carcinomas, perineural tumors, and sections with dense inflammation without apparent tumor. RESULTS: Four cases are described as examples that highlight the potential usefulness of immunostaining of Mohs tissue sections. Anticytokeratin antibodies helped to confirm free tumor margins, thus avoiding the unnecessary sacrifice of normal tissue, and to delineate tumor not identified in hematoxylin and eosin frozen sections. CONCLUSION: Immunohistochemical staining of Mohs micrographic surgical specimens with anticytokeratin antibodies is particularly useful when dense inflammatory infiltrate is present, because the latter may obscure any residual tumor. Application of this technique to difficult cases may prevent tumor recurrences or unnecessary excision of normal tissue.

Immunohistochemical margin control applied to Mohs micrographic surgical excision of dermatofibrosarcoma protuberans.

BACKGROUND: Surgical treatment of dermatofibrosarcoma protuberans has a high rate of recurrence presumably secondary to persistent residual tumor. Recently an antigenic marker, CD34, has demonstrated specificity for this tumor. OBJECTIVE: To improve the microscopic detection of dermatofibrosarcoma protuberans tumor elements in Mohs micrographic surgical sections by incorporating immunohistologic staining. METHODS: Standard Mohs micrographic surgical technique was used, coupled with standard immunohistochemical procedures using an antibody to the CD34 antigen. RESULTS: Immunohistochemical staining with anti-CD34 of Mohs micrographic sections clearly delineated the extent of the tumor elements. CONCLUSIONS: We anticipate that the application of this immunohistochemical-modified Mohs surgical technique will further enhance the detection of insidious portions of tumor thereby enhancing removal and reducing recurrence.