Type:
Educational Exhibit
Keywords:
Cancer, Diagnostic procedure, CT, Abdomen
Authors:
D. Douraghi-Zadeh, K. L. Shahabuddin, R. H. Thomas, E. Moskovic; London/UK
DOI:
10.1594/ecr2013/C-1409
Background
Various pathologies may arise in the retroperitoneum including primary and secondary neoplasms.
Primary retroperitoneal tumours (benign and malignant) are rare.
These are tumours that originate within the retroperitoneum but separate to the retroperitoneal organs.
Retroperitoneal sarcomas (RPS) are very uncommon,
malignant tumours of mesenchymal origin that are responsible for approximately one third of retroperitoneal neoplasms.
The radiologist can play a pivotal role in management by aiding diagnosis and assessing tumour resectibility.
Key information includes the location of the tumour,
its size and the adjacent structures (relationship to the nearby organs and neurovasculature).
RPS generally have a wide range of appearances on imaging and often can be non-specific.
However the presence (or absence) of certain characteristics - fat content,
tumour enhancement/vascularity,
calcification and pattern of disease spread can help to either differentiate or negate certain histological subtypes.
The imaging investigation of choice in RPS is contrast enhanced CT - which can aid in diagnosis,
staging,
management and treatment response.
MRI has poorer spatial resolution but is useful in assessing relationship to vital structures and in particular vasculature.
PET-CT is useful for staging.
A retroperitoneal location can be difficult to distinguish from an intra- peritoneal location.
Key distinguishing features are mass effect causing displacement of retroperitoneal structures (such as pancreas,
adrenal glands and kidneys).
Liposarcomas are the most common type of RPS - accounting for 70%.
Less common histologic subtypes include leiomyosarcomas (15%),
malignant fibrous histiocytomas (MFH).
Rarer pathologies include solitary fibrous tumour and Ewings sarcoma.