Table 1 Key features of some of the primary retroperitoneal masses
From: Solid malignant retroperitoneal masses—a pictorial review
Tumour | Characteristic feature |
|---|---|
Liposarcoma | Macroscopic fat seen in CT or MR. Myxoid variety may have a pseudocystic appearance. Round cell or pleomorphic subtype may be predominantly soft tissue density. |
Leiomyosarcoma | Large heterogeneous solid mass in the retroperitoneum and contiguous involvement of a vessel, is highly suggestive of a leiomyosarcoma. |
Solitary fibrous tumour | Well defined masses with intense heterogeneous enhancement in the arterial phase that persists in the delayed phase. On MRI, multiple flow voids representing vascular channels may be identified on T2-weighted images. |
Presacral myelolipoma | Seen in elderly female patients. Well-defined margins but indistinguishable from liposarcoma on imaging. Sulphur colloid scan may show uptake in the myeloid component. |
Sacrococcygeal teratoma | Seen in children or young patients, more common in females. Variable appearance from cystic to mixed to solid. Bony defects may be present. Intralesional fat or calcification may be present. |
Castleman disease | Intensely enhancing mass, with satellite nodules/nodes. Central low T1 and T2 signal on MRI may correspond to fibrosis. |
Aggressive angiomyxoma | Young females. High T2 signal on MRI with characteristic whorled appearance and whorled appearance post contrast administration |