Sistema FMUSP-HC: Faculdade de Medicina da Universidade de São Paulo (FMUSP) e Hospital das Clínicas da FMUSPFERREIRA, F. de Oliveira2023-12-042023-12-042022de Oliveira Ferreira, F.. Retroperitoneal Tumors. In: . Vascular Surgery in Oncology: SPRINGER INTERNATIONAL PUBLISHING, 2022. p.223-309.978-303097687-3; 978-303097686-6https://observatorio.fm.usp.br/handle/OPI/57249Retroperitoneal tumors are a topic of interest to different specialties. Due to the variety of diagnoses, there are few references that contemplate the theme all together. In this chapter, we chose to analyze the different tumors that may present as retroperitoneal mass, including primary tumors of the retroperitoneal space, primary tumors of retroperitoneal organs that may occupy the retroperitoneal space, intraperitoneal tumors that simulate retroperitoneal lesions, and retroperitoneal lymph node masses. In clinical practice, diagnostic uncertainty regarding the finding of a retroperitoneal mass can lead to misconceptions and be harmful to the patient. Our goal is to address the clinical, radiological, and therapeutic aspects of the different diagnoses. We present a suggestion of the “step by step” to be followed for the diagnostic clarification and also discuss vascular problems related to each diagnosis. The idea is that specialists from different areas can take advantage of the list of diagnoses discussed and keep in mind the diversity of situations associated with the theme. © Springer Nature Switzerland AG 2022.engrestrictedAccessImage diagnosisLymph node massesRetroperitoneal massesRetroperitoneal tumorsRetroperitoneumbookPartCopyright SPRINGER INTERNATIONAL PUBLISHING10.1007/978-3-030-97687-3_7