Abstract: Angiosarcoma is a rare and aggressive tumor with high rates of metastasis and relapse. It shows a particular predilection for the skin and superficial soft tissues. We report three distinct and typical cases of angiosarcoma that were diagnosed in a single dermatology clinic over the course of less than a year: i) Angiosarcoma in lower limb affected by chronic lymphedema, featuring Stewart-Treves syndrome; ii) a case of the most common type of angiosarcoma loated in the scalp and face of elderly man and; iii) a skin Angiosarcoma in previously irradiated breast. All lesions presented characteristic histopathological findings: irregular vascular proliferation that dissects the collagen bundles with atypical endothelial nuclei projection toward the lumen.

Abstract Bacillary angiomatosis is an infection determined by Bartonella henselae and B. quintana, rare and prevalent in patients with acquired immunodeficiency syndrome. We describe a case of a patient with AIDS and TCD4+ cells equal to 9/mm3, showing reddish-violet papular and nodular lesions, disseminated over the skin, most on the back of the right hand and third finger, with osteolysis of the distal phalanx observed by radiography. The findings of vascular proliferation with presence of bacilli, on the histopathological examination of the skin and bone lesions, led to the diagnosis of bacillary angiomatosis. Corroborating the literature, in the present case the infection affected a young man (29 years old) with advanced immunosuppression and clinical and histological lesions compatible with the diagnosis.

Abstract Histiocytoid Sweet's Syndrome is a rare inflammatory disease described in 2005 as a variant of the classical Sweet's Syndrome (SS). Histopathologically, the dermal inflammatory infiltrate is composed mainly of mononuclear cells that have a histiocytic appearance and represent immature myeloid cells. We describe a case of Histiocytoid Sweet's Syndrome in an 18-year-old man. Although this patient had clinical manifestations compatible with SS, the cutaneous lesions consisted of erythematous annular plaques, which are not typical for this entity and have not been described in histiocytic form so far. The histiocytic subtype was confirmed by histopathological analysis that showed positivity for myeloperoxidase in multiple cells with histiocytic appearance.

Abstract: A 59-year-old female patient, previously healthy, immunocompetent, presented left bulbar conjunctiva lesions and nodular-ulcerated lesions on the arms and cervical region, besides left cervical and retroauricular lymphadenopathy. She had previous contact with domestic cats that excoriated her face. The diagnosis was conclusive of disseminated sporotrichosis through clinical and epidemiological history and cultures of skin and ocular secretions. It evolved with good response to oral antifungal therapy.