BRAF mutations in cutaneous melanoma: no correlation with histological prognostic factors or overall survival / Mutações BRAF em melanomas cutâneos: nenhuma correlação com fatores prognósticos e sobrevida global

INTRODUCTION: Molecular biology techniques allow identification of molecular markers such as BRAF and c-Kit gene mutations in melanomas. Studies on genetic alterations in melanomas of South-American patients are sparse. OBJECTIVES: To identify the incidence of BRAF and c-Kit gene mutations in primary cutaneous melanomas in Brazilian patients and to evaluate pathogenetic and prognostic implications of these mutations correlating them with clinical and histopathological data. MATERIAL AND METHODS: Ninety-six surgical specimens of primary cutaneous melanoma and 15 corresponding metastasis were analyzed using TaqMan Real-Time polymerase chain reaction (PCR) assays. RESULTS: In comparison with the medical literature, a relatively low frequency of BRAF mutation in primary (39 percent) and metastatic (40 percent) melanomas and complete absence of c-Kit gene mutations were demonstrated. BRAF mutations arose at an early stage during melanoma progression and were not involved in the transition of thin (< 1 mm) to thick (> 1 mm) melanomas. BRAF mutations are related to patients' younger age and to the pattern of sun exposure, although there was no correlation with any histological prognostic factor or overall survival. CONCLUSION: The identification of both BRAF and c-Kit mutation is not a suitable prognostic indicator in the Brazilian population. Moreover, the relatively low frequency of BRAF mutations brings into question if it actually plays a key role in melanoma pathogenesis.

INTRODUÇÃO: Técnicas de biologia molecular permitem a identificação de marcadores moleculares como mutações dos genes BRAF e c-Kit em melanomas. Estudos de alterações genéticas em pacientes sul-americanos são escassos. OBJETIVOS: Identificar a incidência de mutações dos genes BRAF e c-Kit em melanomas cutâneos primários em uma série de pacientes brasileiros e avaliar as implicações patogenéticas e prognósticas dessas mutações, correlacionando-as com dados clínicos e histopatológicos. MATERIAL E MÉTODOS: Noventa e seis espécimes cirúrgicos de melanomas cutâneos e 15 metástases correspondentes foram analisados por meio da técnica TaqMan Real-Time polymerase chain reaction (PCR). RESULTADOS: Uma frequência relativamente baixa de mutações BRAF em melanomas cutâneos primarios (39 por cento) e metastáticos (40 por cento) em comparação com os dados da literatura e ausência de mutações c-Kit foi demonstrado. Mutações BRAF surgiram em um estágio inicial da progressão do melanoma e não foram envolvidas na transição de melanomas finos (< 1 mm) para grossos (> 1 mm). Essas mutações estavam presentes em pacientes mais jovens e se correlacionaram com o padrão de exposição solar dos pacientes estudados, mas não houve correlação com nenhum fator prognóstico histológico ou sobrevida global dos mesmos. CONCLUSÃO: A identificação de ambas as mutações (BRAF e c-Kit) não servem como indicadores de prognóstico na população brasileira. Além disso, a baixa frequência de mutações BRAF encontrada neste estudo nos faz questionar se essa mutação realmente tem papel-chave na patogênese do melanoma.

Correlation of histopathological patterns in cutaneous melanoma with BRAF mutations / Correlação de padrões histopatológicos de melanomas cutâneos com mutações BRAF

INTRODUCTION: Mutations on BRAF gene located on chromosome 7q are the most frequently found in cutaneous melanomas (60 percent-80 percent). The only study correlating histopathological patterns of cutaneous melanomas with the presence of BRAF mutations was undertaken by Viros et al. in 2008. The authors observed that morphological features of melanomas are associated with BRAF mutations. OBJECTIVES: To correlate histopathological patterns in cutaneous melanoma with the presence of BRAF mutations in order to corroborate the results of the study performed by Viros et al. METHODS: Paraffin embedded surgical specimens of 20 primary cutaneous melanomas with BRAF mutation and 20 specimens without BRAF mutation were evaluated independently by two dermatologists that carried out a blind experiment. The features analyzed were nesting, circumscription, presence of isolated melanocytes in the lesion, size and shape of neoplastic cells, and tumor cell pigmentation. RESULTS: "Nesting" was the most prevalent variable for the determination of melanomas with BRAF mutations according to both observers (r = 0.46; p = 0.04). CONCLUSION: As far as mutational status is concerned, it was not possible to confirm any predictive value for histopathological patterns such as circumscription, presence of isolated melanocytes in the lesion and cytological features. Difficulties in the interpretation of some histological criteria were demonstrated by the variation in the observers' conclusions. It is difficult to state if genetic alterations such as BRAF mutations may serve as biomarkers for melanoma classification.

INTRODUÇÃO: Mutações do gene BRAF localizado no cromossomo 7q são as mais frequentemente encontradas em melanomas cutâneos (60 por cento-80 por cento). O único estudo que correlacionou padrões histopatológicos de melanomas cutâneos com a presença de mutações BRAF foi realizado por Viros et al., em 2008, que observaram que características morfológicas de melanomas estavam associadas a mutações BRAF. OBJETIVOS: Correlacionar padrões histopatológicos de melanomas cutâneos com a presença de mutações BRAF, a fim de confirmar os achados de Viros et al. MÉTODOS: Espécimes em parafina de 20 casos de melanomas cutâneos primários com mutações BRAF e 20 casos sem mutações foram avaliados independentemente por dois dermatologistas sem o conhecimento da presença ou não das mutações. Os padrões analisados foram formação de "ninhos", circunscrição, presença de melanócitos isolados na lesão, tamanho e forma das células neoplásicas e pigmentação das células tumorais. RESULTADOS: A formação de "ninhos" foi a variável com o maior poder de determinação para melanomas com mutações BRAF para ambos os observadores (r = 0,46; p = 0,04). CONCLUSÃO: Não foi possível confirmar nenhum valor preditivo em relação ao status mutacional de um melanoma para os padrões histológicos circunscrição e presença de melanócitos isolados na lesão, bem como para características citológicas. Dificuldades na interpretação de alguns critérios histológicos foram demonstradas pela variação da concordância entre os observadores. É difícil afirmar se alterações genéticas como as mutações BRAF podem servir como biomarcadores para a classificação de melanomas.

Identification of human papilloma virus type 6 in psoriasiform keratosis.

Psoriasiform keratosis is a recently reported unique clinicopathological entity characterized by the appearance of a solitary lesion mimicking seborrheic keratosis, actinic keratosis, or squamous cell carcinoma and histopathologic features closely resembling psoriasis. We report a 74-year-old woman presenting with a solitary, scaly lesion on the dorsum of the left arm of several months duration and histopathologic findings of psoriasiform acanthosis of the epidermis with thinning of the suprapapillary plates and intraepidermal spongiform neutrophilic pustules, consistent with a diagnosis of psoriasiform keratosis. On additional work-up investigation, human papilloma virus type 6 was detected in the tissue examined by polymerase chain reaction technique, an association not described before.

Spectrum of follicular and sebaceous differentiation induced by dermatofibroma.

BACKGROUND: The term "induction" has been used to designate epidermal changes above dermatofibroma. Whereas follicular differentiation has been reported frequently, sebaceous hyperplasia above dermatofibroma is considered a rarity. OBJECTIVE: To characterize all changes overlying dermatofibroma and to determine their frequency. METHODS: Sections cut from 210 consecutive examples of dermatofibroma were stained with hematoxylin and eosin and analyzed for the presence or absence of induction, for the type of change induced, and for features associated with these findings. RESULTS: The epidermis above dermatofibromas was acanthotic, simulating seborrheic keratosis in 62.9% of the cases, and areas of clear and pale cells similar to those of clear cell acanthoma were seen in 18.6%. Induction of adnexal differentiation was encountered in 41% of the cases. Follicular differentiation was seen in 10.9%, all of which showed some follicular germinative cells. In 9.5%, follicular germinative cells were present together with well-circumscribed mesenchymal papillae. In 4%, formation of a complete hair follicle was encountered. In 16.7% of the dermatofibromas, induction of sebaceous lobules was encountered, whereas sebaceous differentiation in the form of mantles was seen in 25.7% of the cases. Not uncommonly, sebaceous structures were arranged in a reticulate pattern similar to that seen in reticulated acanthoma with sebaceous differentiation (12%). CONCLUSIONS: Induction of adnexal structures is more common than currently perceived. Especially, induction of immature and mature sebaceous structures seems to be underrecognized.

Calcification and ossification in eccrine mixed tumors: underrecognized feature and diagnostic pitfall.

BACKGROUND: Eccrine mixed tumors of the skin are rare adnexal neoplasms, and their morphological spectrum is not well established. OBJECTIVE: To highlight the variation of the mesenchymal component of eccrine mixed tumors. METHODS: Among 70, 000 skin biopsies, 5 were diagnosed as eccrine mixed tumors. Cases were studied for clinical, histopathological, and immunohistochemical features (S-100, cytokeratin, epithelial membrane antigen, carcinoembryonic antigen, estrogen receptors, and herceptin receptor (HER-2)). RESULTS: Lesions were well-circumscribed dermal or subcutaneous nodules. Epithelial elements were small round tubules, cords, and individual cell aggregations being larger at the periphery and smaller toward the center. No signs of follicular or sebaceous differentiation were seen. The stroma was mucinous and chondroid, calcification ranging from little to extensive with bone formation in 3 examples giving the impression of a chondroid or osseous neoplasm. S-100 stained epithelial and chondroid stromal cells. Cytokeratin highlighted the silhouette of epithelial elements. Estrogen receptors, EMA, carcinoembryonic antigen, and HER-2 were negative. CONCLUSIONS: Eccrine mixed tumors are distinctive tumors that should not be lumped together with their apocrine counterparts. Extensive ossification and calcification may be present and may eclipse by far the epithelial elements.

Visual perception and consciousness in dermatopathology: mechanisms of figure-ground segregation account for errors in diagnosis.

Visual perception has been the object of research in psychology for almost a century. Little has been written, however, about the effects of perceptive phenomena on methods in medicine that utilize interpretation of two-dimensional images for diagnosis. Starting from the work by Edgar Rubin in the beginning of the last century, this article gives a summary of observations of psychologists who investigated the mechanisms of so-called "figure-ground segregation." These unconscious mechanisms follow rules that explain why certain structures are perceived consciously as a figure, whereas other structures surrounding such a figure are neglected and not perceived consciously in detail. Perception of a structure as a figure can be due to, for example, a convex shape of its contour, proximity of lines around it, closed contours, a simple shape, and attribution of meaning to a structure. In examples from the practice of dermatopathology, those unconscious mechanisms of figure-ground segregation will be shown to be relevant to diagnosis of sections of tissue. The mechanisms help to explain why, for example, ill-defined and concave-shaped structures, stromal differences of neoplasms, interstitial infiltrates and deposits, and simulators of common diseases are often difficult to recognize at first sight. Teachers of dermatopathology need to be aware of these unconscious mechanisms of visual perception because they explain why novices struggle with certain diagnoses and differential diagnoses. Proper instruction about these phenomena, early in the process of training, will prevent a student from being frustrated with misperceptions.

Histopathologic study of scalp psoriasis: peculiar features including sebaceous gland atrophy.

In a study on scalp psoriasis of 19 patients (11 males and 8 females, 15-64 years of age, psoriasis area severity index partial score of the head ranging from 0.5 to 2.8), we came to notice that, apart from the classical criteria for the diagnosis of psoriasis which were present in all cases, in a majority of patients, sebaceous glands were extremely reduced in size. We compared findings of follicular counts and sebaceous glands with a nonpsoriatic group of individuals (n = 26). Ten cases from the psoriatic population presented with completely atrophic glands, most of the time intermingled with larger glands (P = 0.03); not a single case showed sebaceous gland atrophy in the control group. There were no statistical differences regarding total number of hair follicles (P = 0.08), terminal follicles (P = 0.15), vellus follicles (P = 0.39), and telogen follicles (P = 0.58) between the groups. Other unusual features observed in the scalp psoriasis group were dilation of infundibula in 11 cases, a papillomatous epidermal surface in 8 specimens, parakeratosis at the lips of infundibular ostia in 8 specimens, mitotic figures in 7 cases, and necrotic keratinocytes in 14 cases. We conclude that psoriasis of the scalp may present itself with unexpected microscopic findings, among them being atrophy of sebaceous glands. Further studies are necessary to clarify why this atrophy develops and if it is specific to psoriasis.

Circumscribed acral hypokeratosis.

BACKGROUND: Circumscribed acral hypokeratosis (CAH) is an idiopathic condition that typically presents as an acquired, solitary, asymptomatic, well-defined, depressed, flat-based deformity, with a slightly raised border on the palm or, rarely, the sole. Histologically, the lesional epidermis is depressed with a characteristic, abrupt, hyperkeratotic, slightly-raised ridge at the transition from normal skin. OBJECTIVE: We sought to present 3 additional cases of CAH. METHODS: A review of 3 cases of CAH was performed. Liquid phase polymerase chain reaction (PCR) was conducted to evaluate for human papillomavirus (HPV). RESULTS: Three cases of CAH were reviewed. One patient had a history of a burn at the site prior to developing the disorder while another patient, as a child, had a history of verruca plantaris in the same location. Lesions were solitary, involving the palm or sole, in 2 cases and in one case they were multiple involving both the palms and the soles. HPV testing detected HPV type 6 in the lesion of one patient who previously was treated for warts in the same location. Topical fluorouracil, calcipotriol ointment under occlusion, and clobetasol ointment under occlusion were unsuccessful in one patient. LIMITATIONS: In case 2, we were pathology consultants and unable to evaluate the clinical appearance of the lesion. CONCLUSIONS: CAH may involve palms and/or soles. Lesions may be solitary or multiple, and vary widely in size. We believe that CAH most likely represents a reaction pattern developing in response to various stimuli, including trauma, HPV, or both.

www.derm101.com: a growing online resource for learning dermatology and dermatopathology.

The internet is increasingly being used to distribute knowledge in medicine in novel and unconventional ways. In this article, we give a brief introduction into the website www.derm101.com, which was founded by A. B. Ackerman for the purpose of teaching dermatology and dermatopathology. A clinical atlas, online books such as the 3rd edition of his volume "Histologic diagnosis of inflammatory skin diseases", works on clues and differential diagnoses in dermatopathology, a resource on therapeutic strategies in dermatology, a video lecture library on controversial issues in dermatology, the quarterly online journal Dermatopathology: Practical and Conceptual and much more can be found on derm101.com. The site is enriched with new contents biweekly and offers several interactive teaching devices. Currently, www.derm101.com is the most comprehensive online library of dermatology resources.

Use of fumaric acid esters in psoriasis.

Fumaric acid esters (FAE) are chemical compounds derived from the unsaturated dicarbonic acid fumaric acid. The usage of FAEs in treatment of psoriasis was introduced in the late 1950's. In the 1980s more standardized oral preparations of FAEs were developed containing dimethylfumarate (DMF) and salts of monoethylfumarate (MEF) as main compounds. In 1994, Fumaderm an enteric-coated tablet containing DMF and calcium, magnesium and zinc salts of MEF was approved for the treatment of psoriasis in Germany and since then has become the most commonly used systemic therapy in this country. Fumaric acids have been proven to be an effective therapy in patients with psoriasis even though the mechanisms of action are not completely understood. About 50-70% of the patients achieve PASI 75 improvement within four months of treatment and without any long-term toxicity, immunosuppressive effects or increased risk of infection or malignancy. Tolerance is limited by gastrointestinal side effects and flushing of the skin. This article reviews pharmacokinetics, uses, contraindications, dosages and side effects of treatment with FAEs.

Refining criteria for diagnosis of cutaneous infections caused by herpes viruses through correlation of morphology with molecular pathology.

BACKGROUND: Infections of the skin by herpes viruses do not always present themselves in typical fashion. Early diagnosis, however, is crucial for appropriate treatment. Polymerase chain reaction (PCR) allows diagnosis and differential diagnosis of herpes virus infections, but the method is not yet available in large parts of the world, where diagnosis is made based on morphology alone. AIM: To refine criteria for the diagnosis of herpes virus infections of the skin by way of correlation of clinical and histopathologic findings with results of PCR studies. METHODS: We studied 75 clinically diagnosed patients of "zoster," "varicella," and "herpes simplex", to correlate clinical and histopathological findings with results of PCR studies on paraffin embedded biopsy specimens. RESULTS: Clinical suspicion of infection by herpes viruses was confirmed by histopathology in 37% of the cases and by PCR studies in 65% of the cases. Zoster was frequently misdiagnosed as infection with herpes simplex viruses (30%). When diagnostic signs of herpes virus infection were encountered histopathologically, PCR confirmed the diagnosis in 94%. By way of correlation with results of PCR studies, initial lesions of herpes virus infections could be identified to have a distinctive histopathological pattern. Herpetic folliculitis appeared to be a rather common finding in zoster, it occurring in 28% of the cases. CONCLUSION: We conclude that correlation of clinical and histopathological features with results of PCR studies on one and the same paraffin embedded specimen permits identification of characteristic morphologic patterns and helps to refine criteria for diagnosis both clinically and histopathologically.

T-cell dyscrasias in dermatopathology.

Recently, the term "T-cell dyscrasia" has been introduced into the literature of dermatology and dermatopathology. We review the historical background of the term dyscrasia and assess its definition and usage of it in hematopathology and dermatopathology. We learned that the term dyscrasia in the past was associated with meanings very different from one another and that no clear definition and no lucid concept of dyscrasia can be found anywhere in the literature of dermatology and dermatopathology. We conclude that the term dyscrasia in dermatopathology is used mainly to evade problems in interpretation of laboratory findings of a dominant T-cell clone, especially in the circumstance in which a treating physician fails to integrate molecular pathologic data with clinical features and histopathologic findings. Therefore, we suggest that the term lymphomatoid dyscrasia should be abandoned.

Keratosis lichenoides chronica: proposal of a concept.

It has been a subject of controversy whether keratosis lichenoides chronica (KLC) is a distinctive inflammatory disease of the skin or whether it represents a manifestation of another well-known disease, such as lichen planus, lupus erythematosus, or lichen simplex chronicus. In search of clear criteria for diagnosis of KLC the entire literature pertinent to the subject was studied and findings clinical and histopathologic as they were telegraphed in them were compared with a patient of my own experience. Review of the literature reveals more than 60 patients in whom the diagnosis of KLC was made. Three categories emerge based on whether the findings presented in a particular article (1) do not permit any diagnosis to be rendered; (2) do allow a diagnosis specific to be made, such as of lichen simplex, lichen planus, or lupus erythematosus; or (3) do not correspond to any disease well defined, such as lichen simplex, lichen planus, lupus erythematosus, but seem to show attributes morphologic, clinically and histopathologically, that are repeatable. Patients diagnosed as having KLC obviously represent a potpourri of different diseases, the most common of them being lichen simplex chronicus, lichen planus, and lupus erythematosus. Fewer than 25 patients reported on, however, presented themselves with lesions very similar to one another clinically, namely, an eruption that involved the face in a manner reminiscent of seborrheic dermatitis and with tiny papules on the trunk and extremities, which assumed linear and reticulate shapes by way of confluence of lesions. Individual papules were infundibulocentric and acrosyringocentric. Findings histopathologic were those of a lichenoid interface dermatitis affiliated with numerous necrotic keratocytes and covered by parakeratosis housing neutrophils in staggered fashion. These patients seem to have an authentic and distinctive condition that is exceedingly rare. In conclusion, the diagnosis of KLC should be made only for patients who present themselves with features clinical and findings histopathologic that resemble closely those of what is summarized in this article under category 3.

Prurigo pigmentosa: an underdiagnosed disease in patients of Iranian descent?

BACKGROUND: Prurigo pigmentosa (PP) is a rare inflammatory disease of the skin typified by recurrent, pruritic erythematous macules and papules that resolve leaving behind netlike pigmentation. OBJECTIVE: PP is diagnosed most commonly in Japanese women. Preponderance of the disease in other ethnic populations has yet to be identified. METHODS: We conducted a clinicopathologic case study in 4 Iranian women. RESULTS: The clinical diagnosis of PP was confirmed by typical histopathologic findings, elucidating the morphologic spectrum of the disease. LIMITATIONS: The small number of patients in this study is a limitation. CONCLUSION: We suspect that PP may have a proclivity in the Iranian population.

Herpes incognito most commonly is herpes zoster and its histopathologic pattern is distinctive!

Infections of the skin by herpesviruses do not always present themselves in typical fashion. Conventional microscopy is used routinely to confirm infection by herpesviruses, but sometimes typical signs such as multinucleated epithelial cells or "ghosts" of them are not encountered in a specimen (so-called herpes incognito). We studied 35 patients in whom infection with herpesviruses was differentially diagnosed clinically but in whom a biopsy specimen had been taken for confirmation. Only those patients in whom histopathologic findings had been interpreted as being "not diagnostic" of herpesvirus infection by 2 independent dermatopathologists were included. Clinical and histopathologic findings were correlated with results from polymerase chain reaction studies on formalin-fixed paraffin-embedded tissue. Polymerase chain reaction revealed herpesvirus-specific DNA in 12 of 35 specimens, 10 being varicella zoster virus (VZV) positive, 1 herpes simplex virus (HSV)-2 positive, and 1 HSV-1 positive. Ten of these 12 cases presented themselves in very similar fashion (8 VZV, 1 HSV-1, 1 HSV-2). All lesions were macular or papular and typified mostly by dense perivascular and sparse interstitial superficial and deep infiltrates of lymphocytes, sometimes assuming a patchy lichenoid pattern. Infiltrates were prominent in and around adnexal structures, often peppering follicles, sebaceous glands, and eccrine glands. Lymphocytes were also found in the lower part of the epidermis accompanied by a combination of spongiosis and vacuolar alteration. The papillary dermis was often edematous; extravasated erythrocytes in variable numbers were a common finding. Lymphocytes sometimes had large and polygonal nuclei. Neutrophils and nuclear dust were present occasionally; eosinophils were rare. We conclude that herpes incognito most commonly is herpes zoster and its histopathologic pattern is distinctive.

Eosinophilic pustular folliculitis in infancy: not a distinctive inflammatory disease of the skin.

In the standard literature of dermatology and dermatopathology "eosinophilic pustular folliculitis in infancy" is presented as a distinctive inflammatory disease of the skin, to wit, a variant of "Ofuji's eosinophilic folliculitis". Assessment critically of the first publication devoted to the subject revealed a potpourri of findings clinical and histopathologic, with no clear criteria being set forth by the authors to enable diagnosis, with precision. Our review of all articles dedicated to the matter of "eosinophilic pustular folliculitis in infancy" shows that criteria for diagnosis are found with great difficulty. The majority of patients reported on had neither "eosinophilic folliculitis," nor did they present themselves clinically in any way similar to what was originally described by Ofuji. The findings histopathologic told of most commonly were dense and diffuse infiltrates in the dermis that contained many eosinophils, sometimes with periadnexal distribution. We think that the findings reported on in several articles suggest that the patients more likely had a variety of different diseases, among them scabies, insect bites, impetigenized nummular dermatitis, and linear IgA-dermatosis. For clarification of terminology, we suggest that "eosinophilic folliculitis" is better defined as a pattern histopathologic than as a distinctive disease entity. It may be encountered in a variety of conditions (eg, Ofuji's disease, arthropod bites, scabies, or dermatophytosis). In sum, no clear criteria have been established for diagnosis of "eosinophilic pustular folliculitis of infancy" and there is no convincing evidence, at present, that "eosinophilic pustular folliculitis of infancy" qualifies as a distinctive inflammatory disease of the skin.

Transverse sections for diagnosis of alopecia?

Several authors have claimed usage of sections cut horizontally as being preferable to conventional cuts in vertical direction in the diagnosis of alopecias. In this article, we address in critical fashion, all statements that have been made in the literature that seem to favor sections cut horizontally in contrast to sections cut conventionally (ie, vertically) in coming to a diagnosis of diseases of the scalp. Our assessment reveals that the idea of horizontal sections being advantageous compared with sections cut vertically is based largely on the assumption that counting of follicles is the key to a diagnosis with specificity of diseases of the scalp. But a quantitative approach to diagnosis of alopecias is flawed; it does not allow differential diagnosis of common alopecias to be made with certainty. A qualitative approach, however, based on reliable and repeatable criteria applied in sections cut vertically, allows in most instances a diagnosis to be rendered precisely.