A 51-year-old man noticed abdominal swelling and distention with intermittent abdominal pain, early satiety, and decreased appetite over the past several months. A computed tomography (CT) scan of the abdomen showed massive fat containing omental mass with a dominant solid component in the center (Figure A). After a CT guided biopsy (Figure B), he underwent surgical resection of this large retroperitoneal mass revealing a 33-pound macroscopic tumor (Figure C).
Correct answer: E. Retroperitoneal liposarcoma
About 10–15% of adult soft tissue sarcomas are in the retroperitoneum. Liposarcoma is the most common variant and accounts for 20% of all soft tissue sarcomas and over 50% of retroperitoneal sarcomas. Retroperitoneal liposarcoma is a rare, biologically heterogeneous tumor that present considerable challenges due to its size and deep location. Surgery is the mainstay of treatment of non-metastatic retroperitoneal liposarcoma. Whenever possible, macroscopically complete resection should be aimed for, often requiring en-bloc removal of adjacent structures such as the abdominal wall, psoas, or paravertebral muscles. Areas of uncertainty include the necessity of pretreatment biopsy, and the impact of surgical radicality versus disease biology on local control and long-term survival. Patients who undergo complete (macroscopic) or even compartmental resection of the primary tumor have an improved prognosis with a 5-year overall survival rate of 54–70%.
1. Liles JS, Tzeng CWD, Short JJ, Kulesza P, Heslin MJ. Retroperitoneal and intra-abdominal sarcoma. Curr Probl Surg (2009) 46(6):445–503.
2. Craig WD, Fanburg-Smith JC, Henry LR et-al. Fat-containing lesions of the retroperitoneum: radiologic-pathologic correlation. Radiographics. 2009;29 (1): 261-90.
3. Thomas JM. Retroperitoneal sarcoma. Br J Surg (2007) 94(9):1057-1058.
4. Bonvalot S, Raut CP, Pollock RE, Rutkowski P, Strauss DC, Hayes AJ, et al. Technical considerations in surgery for retroperitoneal sarcomas: position paper from E-Surge, a master class in sarcoma surgery, and EORTC-STBSG. Ann Surg Oncol (2012) 19(9):2981–2989.