Primary retroperitoneal masses: what is the differential diagnosis?

Abstract

Primary retroperitoneal masses include a diverse, and often rare, group of neoplastic and non-neoplastic entities that arise within the retroperitoneum but do not originate from any retroperitoneal organ. Their overlapping appearances on cross-sectional imaging may pose a diagnostic challenge to the radiologist; familiarity with characteristic imaging features, together with relevant clinical information, helps to narrow the differential diagnosis. In this article, a systematic approach to identifying and classifying primary retroperitoneal masses is described. The normal anatomy of the retroperitoneum is reviewed with an emphasis on fascial planes, retroperitoneal compartments, and their contents using cross-sectional imaging. Specific radiologic signs to accurately identify an intra-abdominal mass as primary retroperitoneal are presented, first by confirming the location as retroperitoneal and secondly by excluding an organ of origin. A differential diagnosis based on a predominantly solid or cystic appearance, including neoplastic and non-neoplastic entities, is elaborated. Finally, key diagnostic clues based on characteristic imaging findings are described, which help to narrow the differential diagnosis. This article provides a comprehensive overview of the cross-sectional imaging features of primary retroperitoneal masses, including normal retroperitoneal anatomy, radiologic signs of retroperitoneal masses and the differential diagnosis of solid and cystic, neoplastic and non-neoplastic retroperitoneal masses, with a view to assist the radiologist in narrowing the differential diagnosis.

The gamut of primary retroperitoneal masses: multimodality evaluation with pathologic correlation

“…The well-differentiated forms are low-grade malignancies, which usually contain an appreciable amount of fat and rarely metastasize. However, the myxoid liposarcoma with round-cell components and the pleomorphic types show more aggressive behavior, may have a lesser amount of adipose tissue and appear similar to other sarcomas, and generally show higher rates of metastases [6][7][8].…”

“…Liposarcoma frequently recurs within several years, most frequently within 6 months to 2 years, after the initial surgical resection. In routine follow-up computed tomography (CT) examinations, recurrent tumors were found to occur not only along the resection site but also anywhere else in the abdominal cavity [7,8]. CT examinations are useful for the diagnosis and post-operative followup of patients with liposarcoma.…”

Behandlung retroperitonealer Sarkome in Deutschland

“…Die Indikation zur Biopsie ergibt sich aus wesentlichen Differenzialdiagnosen (z. B. Lymphomen), die eine operative Therapie verbieten, sowie der Tatsache, dass nur nach histologischer Sicherung eine multimodale Therapie geplant werden kann [13,14]. Es ist weiterhin fraglich, ob eine Multiviszeralresektion ohne vorherige histologische Sicherung in Anbetracht der möglichen Morbidität auch als alleinige Therapie vertretbar ist.…”

Detection and management of retroperitoneal cystic lesions: A case report and review of the literature

“…�ven if rarely identifi ed in the retro-. �ven if rarely identified in the retroperitoneal space (1,2), cystic lesions are highly challenging regarding the clinical presentation, the diagnostic and the choice of therapeutic approaches (3). Similar masses may be discovered during routinely performed examinations, including abdominal sonography, or may present with symptoms associated with compression of other bodily structures.…”

“…Lesions that occur in the retroperitoneal space are divided into solid masses and cystic lesions, as previously described, and classified (1,2). The precise incidence of these lesions is difficult to define, as the neoplastic lesions are of rare occurrence and the non-neoplastic lesions, such as postsurgical lymphoceles, are more frequent (1,2). �ven if rarely identifi ed in the retro-.…”