From the Guidelines
The most common retroperitoneal sarcoma is liposarcoma (option a). Liposarcomas account for approximately 40-50% of all retroperitoneal sarcomas, making them the predominant subtype in this anatomical location, as supported by the UK guidelines for the management of soft tissue sarcomas 1. These tumors arise from adipose tissue (fat cells) and can range from well-differentiated forms with better prognosis to dedifferentiated, myxoid, or pleomorphic variants that tend to be more aggressive.
Key Characteristics of Retroperitoneal Liposarcomas
- They typically present late due to the expansile nature of the retroperitoneum, allowing tumors to grow to significant size before causing symptoms 1.
- They often present with vague abdominal discomfort, increasing abdominal girth, or symptoms related to compression of adjacent structures.
- While leiomyosarcomas (smooth muscle origin) are the second most common type in this location, and fibrosarcomas and neurosarcomas occur less frequently in the retroperitoneum.
Treatment and Prognosis
- Surgical resection remains the primary treatment for retroperitoneal liposarcomas, though they have a high recurrence rate due to their infiltrative nature and the anatomical complexity of the retroperitoneum 1.
- The prognosis is mostly excellent for atypical lipomatous tumors (ALT), a subtype of liposarcomas, with surgical resection being the usual treatment 1.
- Marginal resections as a complete en bloc specimen, even if classified histopathologically as R1, will give excellent rates of long-term local control 1.
From the Research
Retroperitoneal Sarcoma Types
- The most common histologic types of retroperitoneal sarcomas are liposarcoma and leiomyosarcoma 2, 3.
- Liposarcoma is classified into several types, including well-differentiated, myxoid, round cell, pleomorphic, and dedifferentiated types 3.
- Dedifferentiated liposarcomas are defined by the presence of sharply demarcated regions of non-lipogenic sarcomatous tissue within a well-differentiated tumor 3.
Prevalence of Liposarcoma
- Liposarcoma is the most common histologic type of retroperitoneal sarcoma, found in 5 out of 8 patients in one study 2.
- Another study reported that retroperitoneal liposarcoma is a relatively rare tumor, but it is the most common type of retroperitoneal sarcoma 4.
- A case report also presented a patient with retroperitoneal liposarcoma, highlighting its rarity and variable clinical behavior 5.
Treatment and Prognosis
- Complete surgical resection is the mainstay of curative treatment for retroperitoneal sarcomas, including liposarcoma 2, 4, 6.
- The prognosis of retroperitoneal sarcomas depends on several factors, including tumor grade, histological subtype, complete macroscopic excision, and multifocality 2.
- Adjuvant therapy, such as radiotherapy and chemotherapy, may be required in some cases, but its role is still not clear 2, 5, 6.