ABSTRACT Primary angiosarcomas of the kidney are very rare, but highly aggressive tumors showing poor prognosis. Patients frequently complain of flank pain, hematuria, or a palpable mass. We present a case of primary renal angiosarcoma occurring in a 61-year-old man. CT images depicted a huge exophytic mass (16 cm in diameter) in the right kidney, exhibiting extensive hemorrhage. The mass showed centripetal peripheral nodular enhancement on dynamic contrast-enhanced images. Furthermore, MR imaging revealed a tangled mesh of tumor vessels in the periphery of the mass. We suggest its inclusion in the differential diagnosis of cases of hemorrhagic renal tumors with prominent vasculature.

OBJETIVO: Descrever os achados de imagem de RM no hemangioma hepático com realce perilesional. MATERIAIS E MÉTODOS: Realizou-se uma pesquisa no banco de dados da unidade de RM para identificar todos os casos de hemangioma hepático com realce perilesional entre março de 2008 e julho de 2009. Todos os pacientes foram submetidos a RM pré-contraste em imagens ponderadas em T1 e T2 e em imagens dinâmicas após injeção de gadolínio. Características do hemangioma e do realce perilesional foram avaliadas nas imagens de RM. RESULTADOS: Sete hemangiomas em sete pacientes (cinco homens, duas mulheres; faixa etária entre 41-69 anos; média de 57 anos) foram incluídos no presente estudo. O tamanho das lesões variou de 7 a 20 mm (média de 12,4 mm). Na fase dominante arterial hepática, todos os sete hemangiomas mostraram realce perilesional cuneiforme que se atenuou nas imagens dois minutos após injeção de gadolínio. Quatro dessas lesões demonstraram realce capsular adjacente. CONCLUSÃO: Todos os hemangiomas hepáticos com realce perilesional eram lesões capsulares medindo menos que 2 cm. Tal localização sugere que esses hemangiomas podem recrutar vasos capsulares responsáveis pelo realce perilesional

OBJECTIVE: To describe the MR imaging features of hepatic hemangioma with perilesional enhancement. MATERIALS AND METHODS: A search was performed of the MRI section database to identify all cases of hepatic hemangioma with perilesional enhancement between March 2008 and July 2009. All patients underwent MR examinations including precontrast T1- and T2-weighted images and postgadolinium dynamic images. On MR images, characteristics of the hemangioma and perilesional enhancement were evaluated. RESULTS: Seven hemangiomas in seven patients (five men, two women; age range, 41-69 years; mean, 57 years) were included in this study. Lesion size ranged from 7 to 20 mm (mean, 12.4 mm). On hepatic arterial dominant phase, all seven hemangiomas exhibited wedge-shaped perilesional enhancement which faded on two minutes postgadolinium images. Four of these lesions demonstrated adjacent capsular enhancement. CONCLUSION: All hepatic hemangiomas with perilesional enhancement were < 2 cm capsule-based lesions. This location suggests that these hemangiomas may conscript capsular vessels to account for the perilesional enhancement