1. Giant dedifferentiated liposarcoma of the retroperitoneum Amaro, Alejandra Amolenda, Patricia Anacta, Klarizza CASE REPORT: Vahe S. Tateosian, BE Lourdes Castanon, MD Charles C. Conte, MD

2. 53 y/o Male abdominal pain and right-sided distention that had been increasing for approximately 8 weeks

3. HPI Enlarging right abdomen a dragging sensation in the right side of the upper abdomen and occasional epigastric pain grade 7/10 pain was alleviated slightly by laying on his left side reported early satiety and more frequent urination and bowel movements, with the need to empty his bowels forcefully increasing episodes of insomnia, with frequent awakenings throughout the night a weight loss of 10 lb over the previous year no associated chest pain, shortness of breath, fever, nausea, vomiting, diarrhea, or bloody stools 8 weeks ago Admission

4. Past Medical History No past surgeries.

5. Physical Examination upper and lower quadrants of the right side of the abdomen were found to be significantly distended bowel sounds with dullness to percussion were auscultated over the entire affected region notable epigastric tenderness and questionable hepatomegaly on palpation No lower extremity edema or other positive physical findings were identified

6. Laboratory ResultNormal Values Hemoglobin8.8 g/dl12.5 – 18 g/dl WBC count8.7 X 10 9 /L4-11 X 10 9 /L Platelets695 x 10 9 /L150 – 400 X 10 9 /L Sodium130 mEq/L136 – 145 mEq/L Chloride92 mEq/L101 – 111 mEq/L Glucose454 mg/dL70 – 110 mg/dL Hemoglobin A 1C 14.1 %< 6 %

7. Initial Diagnosis unidentifiable potentially malignant abdominal mass anemia that might result from an underlying malignancy newly discovered diabetes mellitus

8. Abdominal Ultrasonography irregularly marginated mass within the right mid-abdomen – caused obstruction of the right urinary collecting system, and hydronephrosis on the ipsilateral side

9. Abdominal Radiograph no evidence of bowel obstruction, ileus, or free air in the abdomen stool was observed in the descending colon, but the tumor appeared only as a hazy density within the abdomen

10. Computed Tomography

11. scans of the chest, abdomen, and pelvis showed a large, heterogeneous, right-sided abdominal mass that extended across the midline into the left abdomen mass was approximately 31.5 cm long, and its greatest axial dimension measured 23.5 x 17 cm a deformity of the right renal contour at the mid- and lower poles, and the mass arose from within the right kidney mild-to-moderate hydronephrosis of the right kidney and likely obstruction of the ureter

12. Computed Tomography displaced the ascending and transverse colon anteriorly and pushed most of the bowel into the left abdomen no evidence of bowel obstruction right renal artery and vein were patent superior mesenteric vein was displaced into the left upper quadrant inferior vena cava was compressed against the aorta no evidence of liver or lung metastases

13. Magnetic Resonance Imaging suggestive of sarcoma

14. Surgery

15. Exploratory laparotomy, right nephrectomy, and resection of the tumor and mesenteric lymph nodes mass was found to be a 9,395-g (20.67 lb) retroperitoneal tumor circumscribed, well-encapsulated, and encased the kidney without directly infiltrating the parenchyma

16. Histological predominantly vascular myxoid stroma scattered with pleomorphic neoplastic cells and multinucleated giant cells with areas of increased cellularity, confirming a neoplasm frequent atypical mitotic figures and extensive tumor necrosis

18. Diagnosis High-grade dedifferentiated retroperitoneal liposarcoma was made

19. Soft tissue sarcomas always thought to arise de novo and not from pre-existing benign lesions classified according to their presumptive tissue of origin Predisposing factors – genetic predisposition – chronic irritation – previous exposure to radiation, chemotherapy, or chemical carcinogens risks of recurrence and distant metastasis are substantial