Intraperitoneal Liposarcoma: A Case Report and Literature Review of a Rare Entity

Abstract

Liposarcoma is a rare soft-tissue neoplasm originating from adipocytes. The exact cause of liposarcoma is unknown and symptoms vary depending on the tumor's location. A 49-year-old man presented to the emergency room complaining of epigastric pain radiating to the back and right upper quadrant. Cross-sectional imaging revealed a large upper abdominal mass that was thought to be a gastrointestinal stromal tumor (GIST) arising from the duodenum at first. The patient underwent en-bloc resection of the mass and was planned for adjuvant chemotherapy. Subsequently, multiple tissue samples were examined, leading to the final diagnosis of de-differentiated liposarcoma. The patient eventually developed multiple recurrences and was subjected to re-resection surgeries and three different chemotherapy regimens. Given the rarity of the disease, no standardized therapy plan is available, highlighting the need for more case reports/series and trials to broaden our understanding of this disease.

Keywords: dedifferentiated liposarcoma; intra-peritoneal; liposarcoma; mdm2; recurrent sarcoma.

Figure 1. Contrast-enhanced CT images of the abdomen (axial view)

CT: computerized tomography Axial contrast-enhanced CT images showing a large complex mass of cystic and solid nature (white arrows) in the paraduodenal area extending into the porta hepatis. The mass appears inseparable from the adjacent structures, including the liver, portal triad, duodenum, pancreas, and pylorus, with no definite organ or vascular invasion.

Figure 2. T2 weighted MR images

MR: Magnetic resonance; FSE: Fast-spin echo; DWI: Diffusion-weighted imaging; ADC: Apparent diffusion coefficient. Axial (A) and coronal (B) T2 weighted MR images single shot FSE show huge complex cystic and intermediate hyperintense soft tissue mass in the paraduodenal region extending into the portahepatis. The mass appears inseparable from the duodenum and is abutting the liver and pancreas. Axial fat-suppressed T2 weighted MR image (C) shows the complex nature of the mass with cystic changes and soft tissue components that demonstrate intermediate high signal intensity. Axial DWI (D) and ADC maps (E) (b value = 800 s/mm²) showed high signal intensity on DWI and low signal intensity on the ADC maps of the soft tissue components, indicating diffusion restriction. Axial T1 gradient echo in-phase (F) and out-of-phase (G) MR images showed a predominantly low T1 signal intensity mass with areas of high signal intensity without signal drop in the out-of-phase to suggest fat components. Axial (H) and coronal (I) contrast-enhanced MR in the portal venous phase showed heterogeneous enhancement of the soft-tissue components of the mass. The yellow arrows mark the mass being described.

Figure 3. Contrast-enhanced CT images in the portal venous phase

CT: computerized tomography Axial (A) and coronal (B) contrast-enhanced CT images in the portal venous phase show the huge heterogeneously enhancing complex mass measuring 20.5 x 14.8 x 11 cm (white arrows). The mass appears inseparable from the adjacent organs and compresses the common bile duct causing intrahepatic biliary duct dilatation. Enlarged retroperitoneal lymphadenopathy has also developed (not shown).

Figure 4. Tomography images four months after tumor resection

CT: Computerized tomography; PET: Positron emission tomography. Axial (A) contrast-enhanced CT image in portal venous phase shows tumor recurrence/residual (white arrow). Axial fused fluorodeoxyglucose (18F) PET/CT image (B) shows hypermetabolic recurrent/residual mass (white arrow).

Figure 5. CT scans images a month after the second cytoreductive surgery

CT: Computerized tomography Axial (A) and coronal (B) CT scans done a month after the second cytoreductive surgery showed a large internal hematoma with features of active venous bleeding (red arrows). Multiple peritoneal nodules showed an increase in size; the subhepatic and gastrohepatic nodules are shown here (white arrows).