Abstract: Rosai-Dorfman disease is a benign histiocytic proliferative disorder of unknown etiology. The disease mainly affects lymph node tissue, although it is rarely confined to the skin. Here, we describe a 53-year-old woman with purely cutaneous Rosai-Dorfman disease. The patient presented with a large pigmented plaque on her left leg, and sparse erythematous papules on her face and arms. A complete clinical response was achieved with thalidomide, followed by recurrence at the initial site one year later. The histological examination displayed the typical features of Rosai-Dorfman disease in the recent lesions but not in the older lesions. In the setting of no lymphadenopathy, the histopathological features of Rosai-Dorfman disease are commonly misinterpreted. Therefore, awareness of the histological aspects present at different stages, not always featuring the hallmark microscopic signs of Rosai-Dorfman disease, is particularly important for a correct diagnosis of this rare disorder.

Abstract: Benign follicular tumors comprise a large and heterogeneous group of neoplasms that share a common histogenesis and display morphological features resembling one or several portions of the normal hair follicle, or recapitulate part of its embryological development. Most cases present it as clinically nondescript single lesions and essentially of dermatological relevance. Occasionally, however, these lesions be multiple and represent a cutaneous marker of complex syndromes associated with an increased risk of visceral neoplasms. In this article, the authors present the microscopic structure of the normal hair follicle as a basis to understand the type and level of differentiation of the various follicular tumors. The main clinicopathological features and differential diagnosis of benign follicular tumors are then discussed, including dilated pore of Winer, pilar sheath acanthoma, trichoadenoma, trichilemmoma, infundibuloma, proliferating trichilemmal cyst/tumor, trichoblastoma and its variants, pilomatricoma, trichodiscoma/fibrofolliculoma, neurofollicular hamartoma and trichofolliculoma. In addition, the main syndromes presenting with multiple follicular tumors are also discussed, namely Cowden, Birt-Hogg-Dubé, Rombo and Bazex-Dupré-Christol syndromes, as well as multiple tumors of follicular infundibulum (infundibulomatosis) and multiple trichoepitheliomas. Although the diagnosis of follicular tumors relies on histological examination, we highlight the importance of their knowledge for the clinician, especially when in presence of patients with multiple lesions that may be the cutaneous marker of a cancer-prone syndrome. The dermatologist is therefore in a privileged position to recognize these lesions, which is extremely important to provide further propedeutic, appropriate referral and genetic counseling for these patients.

Relata-se o caso de um homem de 20 anos de idade com poroceratose punctata, caracterizada por múltiplas pápulas queratósicas e depressões, com disposição linear localizada à região palmar da mão e 5º dedo esquerdos, com cerca de 8 anos de evolução. O estudo histológico mostrou presença de depressão da epiderme, preenchida por característica lamela cornóide. Foi realizada revisão da literatura e ressaltado o seu diagnóstico diferencial.

This case report involves a 20-year-old man with unilateral punctate porokeratosis. The patient presented an 8-year history of numerous asymptomatic keratotic papules and pits with linear distribution on his left pal-mar surface and fifth finger of the left hand. Histopathological examination of the keratotic plug revealed findings of distinct epidermal depressions containing cornoid lamellae. This report review draws attention to differential diagnoses of punctate porokeratosis.

FUNDAMENTOS: O cancro cutâneo não-melanoma, designação conjunta para os carcinomas basocelulares e espinhocelulares, é o tipo de neoplasia cutânea maligna mais frequente. OBJETIVOS: Caracterização epidemiológica da população diagnosticada com cancro cutâneo não-melanoma. MÉTODOS: Foi realizada uma análise retrospectiva dos doentes portadores de cancro cutâneo não-melanoma identificados por análise histológica de todas as biopsias cutâneas incisionais ou excisionais ao longo de 5 anos (2004-2008) num serviço de Dermatologia. RESULTADOS: foram identificados 3075 cancros cutâneos não-melanoma, representando 88% do total de neoplasias malignas diagnosticadas no mesmo período (n=3493). Destes, 68,3% eram carcinomas basocelulares. No seu conjunto, a população de cancro cutâneo nãomelanoma era predominantemente constituída por indivíduos idosos e do sexo feminino, tendo sido observado um aumento consistente da freqüência ao longo do período avaliado (5,25%/ano). A maioria dos cancros cutâneos não-melanoma (n=1443, 81,7%) foi identificada nas áreas de pele foto-exposta, representando 95,1% de todas as neoplasias malignas em áreas foto-expostas. O cancro cutâneo não-melanoma foi a neoplasia mais representativa na generalidade das áreas topográficas, à exceção do abdômen e da pélvis, representando, em particular, mais de 95% das neoplasias malignas da face, da região cervical e do couro cabeludo. O carcinoma basocelular foi o cancro cutâneo não-melanoma predominante em todas as localizações, à exceção dos membros inferiores e superiores, lábio inferior e da área genital, onde o carcinoma espinhocelular representou, respectivamente, 77,7%, 77,4%, 94,7% e 95,3% dos casos. CONCLUSÕES: O cancro cutâneo não-melanoma, como neoplasia maligna cutânea mais freqüente, deverá ser alvo de uma monitorização regular, com vista à determinação da sua dinâmica epidemiológica, da eficácia das medidas preventivas e adequação dos recursos de saúde.

BACKGROUND: Non-melanoma skin cancer, a common designation for both basal cell carcinomas and squamous cell carcinomas, is the most frequent malignant skin neoplasm. OBJECTIVE: Epidemiologic characterization of the population with Non-melanoma skin cancer. METHODS: Retrospective analysis of all patients diagnosed with Non-melanoma skin cancer based on histopathologic analysis of all incisional or excisional skin biopsies performed between 2004 and 2008 in a Department of Dermatology. RESULTS: A total of 3075 Non-melanoma skin cancers were identified, representing 88% of all malignant skin neoplasms (n=3493) diagnosed in the same period. Of those, 68,3% were basal cell carcinomas. Most Non-melanoma skin cancer patients were female and over 60 years old. Of all Non-melanoma skin cancer, 81,7% (n=1443) were located in sun-exposed skin, and represented 95,1% of malignant skin neoplasms in sun-exposed skin. Non-melanoma skin cancer was the most frequent malignant skin neoplasm in most topographic locations, except for abdomen and pelvis - over 95% of all malignant skin neoplasms in the face, neck and scalp were Non-melanoma skin cancer. Basal cell carcinomas were clearly predominant in all locations, except in upper and lower limbs, lower lip and genitals, where squamous cell carcinomas represented respectively 77,7%, 77,4%, 94,7% and 95,3% of the Non-melanoma skin cancers. CONCLUSION: Being the most common skin cancer, Non-melanoma skin cancer should be under constant surveillance, in order to monitor its epidemiologic dynamics, the efficiency of preventive measures and the adaptation of the healthcare resources.

O histiocitoma fibroso é tumor heterogéneo composto por fibroblastos, histiócitos e vasos sanguíneos. Efectuamos uma revisão histopatológica retrospectiva de 95 biopsias de histiocitomas fibrosos do nosso arquivo dos últimos 3,5 anos, com o objectivo de avaliar a localização, delimitação, alteração da epiderme, indução folículo-sebácea, celularidade, vascularização, padrão do colagénio e tipo de células constituintes. Na maioria das biopsias, confirmamos as características histopatológicas clássicas dos histiocitomas fibrosos. Achados interessantes observados no nosso estudo foram presença de células nódulos linfoides, mastócitos e infiltrado de células inflamatórias.

Fibrous histiocytoma (FH) is a heterogeneous tumor composed of fibroblasts, histiocytes, and blood vessels. We conducted a retrospective histopathologic analysis of 95 biopsies, performed over the last 3.5 years, of fibrous histiocytomas to analyze the location, delimitation, epithelial changes, induction of folliculo-sebaceous structures, cellularity, vascularity, collagen pattern, and types of composite cells of the FH. In the majority of the biopsies, we confirmed the classical histopathologic features of fibrous histiocytomas. The presence of lymphoid nodules, mast cells, and sparse infiltrate of inflammatory cells was an interesting finding observed in our study.