Abstract Onychocytic matricoma is a newly described tumor of the nail matrix. Clinically, it presents with localized thickening of the nail plate and melanonychia. Histologically, it represents a benign acanthoma of onychocytes. There are 8 cases reported in the literature. A 12-year-old girl presented with localized melanonychia and concurrent thickening of the nail plate restricted to the area of pigmentation affecting the right thumb, with no history of trauma or pain. We report a case of this rare tumor occurring in late childhood and provide a comprehensive review of its clinical presentation and differential diagnosis. Both clinicians and dermatopathologists should be aware of the presentation of onychocytic matricoma and include it in their scope of diagnosis of longitudinal nail bands.

Abstract: The classification of cutaneous lymphomas is multidisciplinary and requires the correlation between clinical, histopathological, immunohistochemical, and molecular diagnostic elements. In this article, we present four different cases of CD30-positive T-cell lymphoma with cutaneous manifestations. We compare cases with definitive diagnosis of papulosis lymphomatoid type C, primary cutaneous anaplastic large T-cell lymphoma, systemic anaplastic large T-cell lymphoma with secondary skin involvement, and mycosis fungoides with large cell transformation, highlighting the importance of clinicopathological correlation to classify these cases.

Abstract Woolly hair nevus is a rare condition characterized by a structural anomaly of the hair, restricted to certain areas of the scalp. The hair becomes coiled and slightly hypopigmented. The term woolly hair refers to changes that affect all the scalp and has a hereditary character. We present a case of woolly hair nevus, that developed at the age of 2 years, associated with dental diastema and verrucous epidermal nevus.

Abstract The use of tumor necrosis factor antagonists (anti-TNF) has become a usual practice to treat various inflammatory diseases. Although indicated for the treatment of psoriasis, anti-TNF may paradoxically trigger a psoriasiform condition. We present a case of a female patient who, during the use of infliximab for rheumatoid arthritis, developed psoriasis. In an attempt to switch anti-TNF class, we observed a cumulative worsening of the lesions requiring suspension of the immunobiological agent and the introduction of other drugs for clinical control. The therapeutic challenge of this paradoxical form of psoriasis is the focus of our discussion. The use of another anti-TNF in these patients is a matter of debate among experts.

Abstract Childhood linear immunoglobulin A dermatosis is a rare autoimmune vesiculobullous disease. It results in linear deposition of autoantibodies (immunoglobulin A) against antigens in the basal membrane zone, leading to subepidermal cleavage. Additional depositions of immunoglobulin G and complement-3 might occur. It is still debated whether concomitant findings of immunoglobulins A and G should be considered a subtype of this dermatosis or a new entity. Further studies are needed to recognize this clinical variant.

Abstract: Melanomas can arise either de novo (70%) or from pre-existing melanocytic lesions (30%). Of the latter, most cases arise at the dermoepidermal junction from small congenital or acquired non-blue nevi while only a few arise from blue nevi, notably the cellular subtype and less commonly the common (dendritic) type. Melanomas that arise from blue nevi usually occur on the scalp with greater frequency, as in the case described. Although previous studies have discussed melanoma arising from giant congenital blue nevi, few have discussed those arising from intermediate blue nevi. We present a case of a 52-yearold man with melanoma on the scalp evolving from an intermediate congenital common blue nevus.

Abstract Leprosy is a chronic disease characterized by manifestations in the peripheral nerves and skin. The course of the disease may be interrupted by acute phenomena called reactions. This article reports a peculiar case of type 2 leprosy reaction with Sweet's syndrome-like features as the first clinical manifestation of leprosy, resulting in a delay in the diagnosis due to unusual clinical presentation. The patient had clinical and histopathological features reminiscent of Sweet's syndrome associated with clusters of vacuolated histiocytes containing acid-fast bacilli isolated or forming globi. Herein, it is discussed how to recognize type 2 leprosy reaction with Sweet's syndrome features, the differential diagnosis with type 1 leprosy reaction and the treatment options. When this kind of reaction is the first clinical presentation of leprosy, the correct diagnosis might be not suspected clinically, and established only with histopathologic evaluation.

Abstract Cytomegalovirus is an opportunistic virus that commonly affects immunosuppressed patients. Cutaneous involvement by this virus is rare and occurs in significantly immunocompromised hosts, with a poor prognosis. Skin ulcers may represent the first sign of systemic infection by cytomegalovirus in these patients. Herein, a case of a systemic infection by Cytomegalovirus presenting as genital and oral ulcers in a kidney-transplant recipient is reported.

Abstract Milker's nodule is an occupational viral skin disease of universal distribution, caused by the Paravaccinia virus and that occurs in individuals who deal with dairy cattle herds. We describe a case acquired due to lack of use of PPE (Personal Protective Equipment) and perform a literature review.

We report the case of an 11-year-old male patient with a histopathological and immunohistochemical diagnosis of dermatofibroma with an atypical clinical presentation on the right forearm. Although dermatofibroma is considered a benign skin tumor, some of its differential diagnoses, such as dermatofibrosarcoma protuberans and malignant fibrous histiocytoma, are truly aggressive. Lesions with atypical clinical aspects and topology associated with specific histopathological variants are some of the criteria for complete tumor excision.

Os autores relatam um caso de esquistossomose cutânea ectópica em uma paciente de 35 anos que apresentou máculas e pápulas eritematosas agrupadas na nádega esquerda. O diagnostico não foi suspeitado durante a avaliação clínica, tendo sido obtido através da visualização dos ovos no exame histopatológico.

The authors report a case of ectopic cutaneous schistosomiasis in a 35 year-old female who presented clustered reddish macules and papules on the left buttock. The diagnosis was not suspected during clinical evaluation and required visualization of Schistosoma mansoni eggs on sections of tissue.

A dermatose bolhosa por IgA linear tem sido crescentemente associada com doenças inflamatórias intestinais, especialmente a retocolite ulcerativa. Relatamos o caso de um adolescente masculino, 13 anos de idade, com retocolite ulcerativa diagnosticada 11 meses antes, que desenvolveu vesículas, pústulas e erosões na pele da face, do tronco e das nádegas e na mucosa oral. A investigação revelou doença bolhosa subepidérmica rica em neutrófilos e deposição linear de IgA ao longo da junção dermoepidérmica, estabelecendo o diagnóstico de dermatose bolhosa por IgA linear. O paciente experimentou controle insatisfatório dos sintomas cutâneos e gastrointestinais apesar do uso de adalimumab, mesalazina, prednisona e dapsona por alguns meses. Após colectomia total, ele apresentou remissão completa das lesões cutâneas, sem necessidade de medicações durante os dois anos de seguimento. Neste artigo, revisamos os casos previamente relatados desta associação e debatemos o papel da retocolite ulcerativa no desencadeamento da dermatose bolhosa por IgA linear.

Linear IgA dermatosis has been increasingly associated with inflammatory bowel diseases, particularly ulcerative colitis. A 13-year-old male patient with an 11-month history of ulcerative colitis developed vesicles, pustules and erosions on the skin of the face, trunk and buttocks and in the oral mucosa. The work-up revealed a neutrophil-rich sub-epidermal bullous disease and linear deposition of IgA along the dermoepidermal junction, establishing the diagnosis of linear IgA dermatosis. The patient experienced unsatisfactory partial control of skin and intestinal symptoms despite the use of adalimumab, mesalazine, prednisone and dapsone for some months. After total colectomy, he presented complete remission of skin lesions, with no need of medications during two years of follow-up. A review of previously reported cases of the association is provided here and the role of ulcerative colitis in triggering linear IgA dermatosis is discussed.

A pitiríase amiantácea, também chamada de pseudotínea amiantácea, é compreendida como uma síndrome clínica que acomete o couro cabeludo. Representa um padrão de reação a diversas dermatoses inflamatórias. Os autores procuram estabelecer a correlação entre características clínicas, dermatoscópicas e de microscopia ótica, através da análise do tufo de cabelos agregados pelas escamocrostas, submetido a processamento histológico.

Pityriasis Amiantacea, also known as pseudotinea amiantacea, is a clinical syndrome which affects the scalp, having a reaction pattern reported to occur in several inflammatory dermatoses. The authors seek to establish the correlation between its clinical, dermoscopic and light microscopy features through the analysis of scale- encrusted hair tufts submitted to histological processing.