Soft-tissue sarcomas are rare tumors and represent less than 1% of all malignancies. Of all soft tissue sarcomas 10% to 15% are located in the retroperitoneum. Liposarcomas are the most common soft tissue sarcomas in adults and the second most frequent retroperitoneal tumours (1). They are most commonly located in the soft tissues of the extremities, but other sides such as retroperitoneum can be involved (2). Retroperitoneal liposarcomas (RLs) grow slowly in the very expandable retroperitoneal space in the deeply hidden and clinically silent retroperitoneum. Total resection of the tumour is the aim, including adjacent organs if necessary. But, its prognosis is poor due to tumor relapse and only complete surgical removal produces a "cure" (3).Multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) are very important for diagnosis of RLs with fast multiplanar imaging techniques especially for huge ones. Hereby we demonstrated the facility of multiplanar evaluating of giant RLs with MDCT and MRI on two of our patients.
Case reports
Case 1A 52-year-old woman admitted to our hospital with a one year history of abdominal pain, distension, dyspepsia, and alteration of intestinal habits. She did not have any loss in weight, on the contrary she put on weight. On physical examination, her abdomen had a marked distened liposarcoma, showed CT attenuation and MR signal intensity that approximated the characteristics of muscle (Fig. 1). The tumor did not involve the major vascular structures, and the organs. The lesion was hypointense relative to muscle on T1 and T2 weighted TSE images, and showed slightly enhancement ( Fig. 2). MDCT attenuation and MRI signal intensity of the lesion was equal to fat tissue and with drop-out on fat-suppressed STIR images (Fig. 3). The T1 weighted criteria for well-differentiated liposarcoma were thick septation and nodularities with non-fatty signal intensity within tumors as this case. Thus, imaging on fat-suppressed STIR images, lesion was considered well-differentiated liposarcoma also when linear or nodular well-defined hyperintens septas were detected inside suppressed fatty lesion. No distant metastasis was detected. Histological examination revealed a well-differentiated liposarcoma.
Case 2A 70-year-old woman was admitted to emergency department of our hospital with severe abdominal pain, distension, nausea, dyspepsia, anorexia, and abdominal tenderness. She had almost one-year of abdominal pain, and her complaints had significantly increased in the past two months. The abdomen was enlarged and a very large soft mass was palpable throughout the abdomen. Laboratory findings showed no significant changes. Abdominal ultrasound revealed a hypoechoic huge mass in retroperitoneal region that was displacing the right colon, and right kidney anteriorly and medially. MDCT imaging demonstrated a very large retroperitoneal mass of fat density that was filling right abdomen-pelvic cavity totally and left abdomen cavity partially. The lesion was comsion and a palpable huge ma...