Abstract Secondary osteoma cutis is a phenomenon that may occur in several conditions. When it occurs in a melanocytic nevus it is named osteonevus of Nanta, an event considered uncommon and characterized by the presence of bone formation adjacent or interposed with melanocytic cells. There are reports of its occurrence in various melanocytic lesions, being more frequently associated with intradermal nevus. We report a case of osteonevus of Nanta in combined nevus, possibly the first description of this association.

Lacaziosis or Jorge Lobo's disease is a fungal, granulomatous, chronic infectious disease caused by Lacazia loboi, which usually affects the skin and subcutaneous tissue. It is characterized by slow evolution and a variety of cutaneous manifestations with the most common clinical expression being nodular keloid lesions that predominate in exposed areas. We report the case of a patient who had an unusual clinical presentation, with a single-plated lesion on the back. Histopathological examination confirmed the diagnosis of Lacaziosis.

A ocorrência de carcinoma espinocelular sobre lesões cutâneas de longa evolução é clássica em cicatrizes de queimadura e úlceras crônicas de etiologia variada, inclusive infecciosa. Na literatura, são raros os casos de pacientes com lobomicose de longa evolução que desenvolveram CEC. O seguimento cuidadoso desses pacientes é importante, pois, nas áreas de traumas, ulcerações e cicatrizes crônicas pode ocorrer degeneração carcinomatosa.

The occurence of squamous cell carcinoma on long-lasting ulcers is classic. Malignant transformation may occur on burn scars and chronic ulcers of varying etiology, including infectious agents. Transformation of old lobomycosis lesion scars into squamous cell carcinoma has been rarely reported. Careful and long-term follow-up of such patients is important to avoid carcinomatous transformation.

O mixofibrossarcoma, previamente conhecido como histiocitoma fibroso maligno, variante mixoide, é um tumor raro, de origem mesenquimal, composto por células fusiformes e estroma mixoide. Acomete mais idosos, envolvendo extremidades inferiores e estendendo-se, em sua maior parte, até a derme e o subcutâneo. Apresenta altas taxas de recorrência e para seu diagnóstico é fundamental a realização de uma biópsia profunda. Relataremos o caso de um mixofibrossarcoma de alto grau, caracterizado por lesão tumoral de crescimento rápido e pela presença de marcado pleomorfismo celular e componente mixoide em abundância

Myxofibrosarcoma, previously known as malignant fibrous histiocytoma, myxoid variant, is a rare tumor of mesenchymal origin, composed of spindle cells and myxoid stroma. It mainly affects elderly people, involving the lower extremities and frequently extending to the dermis and subcutaneous tissue. The tumor presents high rates of recurrence, and a deep biopsy is required to obtain the correct diagnosis. We report a case of high-grade mixofibrossarcoma characterized by a rapidly growing tumor and the presence of marked cellular pleomorphism and an abundant myxoid matrix

Hemangioma é o tumor mais comum da infância, frequentemente situado na cabeça e pescoço. A órbita é frequentemente acometida e indica intervenção precoce e agressiva para evitar sérias complicações visuais. Reportam-se dois casos, nos quais há impedimento da visão no primeiro e, no segundo, um hemangioma profundo acomete áreas adjacentes, confirmado por exame radiológico. Demonstra-se sucesso terapêutico após corticoterapia sistêmica agressiva, evitando sequelas visuais permanentes, além do resultado estético satisfatório. O tratamento de escolha é o corticosteroide oral, devendo ser conduta individualizada e com bom seguimento clínico dos possíveis efeitos adversos

Hemangioma is the most common tumor of childhood and is commonly located on the head or neck. The orbit is often affected and early and aggressive intervention is required to prevent serious visual complications. This paper reports on two cases. In the first case, the patient's vision was impaired, while in the second case a deep hemangioma affecting adjacent areas was confirmed radiologically. Treatment with aggressive systemic corticotherapy was successful, thus avoiding permanent damage to the patients' vision. Furthermore, esthetic outcome was satisfactory. The treatment of choice is oral corticosteroids and management should be individualized and should include careful follow-up to monitor possible adverse effects

O rabdomiossarcoma é o tumor de partes moles mais comum na infância, sendo raro o acometimento exclusivamente cutâneo. Apresenta-se caso de criança com nódulo doloroso na face, cuja análise histopatológica e imunoistoquímica confirmou tratar-se de rabdomiossarcoma, o qual foi conduzido por equipe multidisciplinar. Os tumores de partes moles são responsáveis por 6% de todos os tumores infantis; destes, 53% são rabdomiossarcomas, que podem acometer qualquer sítio. A manifestação como nódulo dérmico é incomum, representando um desafio diagnóstico, já que não possui características clínicas que o diferenciem de outras patologias.

Rhabdomyosarcoma is the most common soft tissue tumor in childhood; however, it rarely affects only the skin. This case report describes a child with a painful nodule on her face. Histopathology and immunohistochemistry confirmed the diagnosis of rhabdomyosarcoma, and a multidisciplinary team then followed up the patient. Soft tissue tumors are responsible for 6% of all childhood tumors, and 53% of these are rhabdomyosarcomas, which may affect any part of the body. Presentation in the form of skin nodules is rare and represents a diagnostic challenge, since there are no clinical characteristics that differentiate this condition from other pathologies.

Síndrome de Laugier-Hunziker é caracterizada por hiperpigmentação macular adquirida, idiopática das mucosas oral e genital, que pode estar associada à melanoníquia longitudinal. Relata-se caso de melanoníquia longitudinal das mãos e pés, sinal de Hutchinson e pigmentação lenticular dos lábios e mucosa oral. A histologia é típica, com amplo diagnóstico diferencial. Trata-se de entidade rara e benigna, que deve ser incluída na diagnose diferencial das hiperpigmentações mucocutâneas.

Laugier-Hunziker syndrome is an acquired macular hyperpigmentation of the oral and genital mucosa, often associated with longitudinal melanonychia. We report a case of longitudinal melanonychia on ?ngernails and toenails, hutchinson's signal and lenticular pigmentation of her lips and oral mucosa. Histopathological analysis is tipical and had a broad differential diagnosis. This is a rare and benign entity, which should be included in the differential diagnosis of mucocutaneous hyperpigmentation.