CONTEXTO: Lesões de tecido adiposo são as mais comuns de partes moles em adultos. RELATO DE CASO: Descrevemos o caso de uma paciente do sexo feminino, 33 anos, com lesão em partes moles do joelho esquerdo diagnosticada como lesão lipomatosa fibrohistiocítica hemossiderótica. Essa lesão foi descrita pela primeira vez em 2000, acometendo preferencialmente a região do tornozelo de mulheres de meia-idade com história de trauma prévio local. Recidiva da lesão é comum devido à ressecção incompleta e não há até o momento relato de metástase. Após revisão da literatura, descrevemos as características clínicas, radiológicas, morfológicas, imunoistoquímicas assim como seus principais diagnósticos diferenciais.

CONTEXT: Lesions of the adipose tissue are the most common type of soft-tissue lesion among adults. CASE REPORT: We describe the case of a 33-year-old female patient with a soft-tissue lesion in her left knee that was diagnosed as a hemosiderotic fibrohistiocytic lipomatous lesion. This type of lesion, which was described for the first time in 2000, preferentially affects the ankle region of middle-aged women with a history of previous local trauma. Lesion recurrence is common, caused by incomplete resection, although there have not yet been any reports of metastases. After a review of the literature, we describe the clinical, radiological, morphological and immunohistochemical characteristics, along with their main differential diagnoses.

Leiomyosarcoma of the inferior vena cava is an extremely rare tumor, and it is reported to have a poor prognosis. The clinical findings are nonspecific and may precede the diagnosis by several years. Symptoms depend on the location and extension of the tumor. A complete surgical resection is the only proven therapeutic modality that prolongs the survival in patients with this lesion. We report a case of a 50 year-old patient with inferior vena cava leiomyosarcoma, who was submitted to a surgical treatment.

Com os objetivos de conhecer melhor a morfologia do megacólon chagásico e contribuir para o conhecimento da patogênese da fibrose dos megas, realizou-se estudo morfométrico na muscular circular do cólon, contando-se o número de mastócitos e medindo o conjuntivo fibroso nessa camada. Foram avaliados anéis do sigmóide distal de 15 chagásicos com megacólon (MCC), 15 sem megacólon (CSMC) e 15 não chagásicos (NC). Os anéis foram fixados em formol, incluídos em parafina, cortados com 7mm de espessura e corados por Azan-Heidenhain e Giemsa. O número de mastócitos e a fibrose foram maiores no grupo com MCC em relação ao CSMC e NC (p < 0,05; teste de Kruskal-Wallis); não houve diferença significante entre os dois últimos grupos. Diante destes achados, é possível, que haja relação entre mastocitose e fibrose no megacólon chagásico, como já se demonstrou em outras doenças.

A morphometric study of the circular colon musculature was performed, in which the mast cell count was determined and the connective fibrous tissue in this layer was measured. The objective was to gain better understanding of Chagas megacolon morphology and contribute towards the knowledge of fibrosis pathogenesis in Chagas megas. An evaluation was made of 15 distal sigmoid rings from Chagas patients with megacolon (MCC), 15 without megacolon (CSMC) and 15 non-Chagas patients (NC). The rings were fixed in formol, embedded in paraffin, and 7mm thick sections were cut and stained using Azan-Heidenhain and Giemsa. The mast cell count and fibrosis were greater in the MCC group than in the CSMC and NC groups (p < 0.05; Kruskal-Wallis test) and there was no significant difference between the latter two. The fibrosis and increased mast cell count in the colon musculature of the MCC group possibly indicates that there is a relationship between mastocytosis and fibrosis, as has already been demonstrated in other pathologies.