A 75-year-old woman was admitted at the Affiliated Hospital of Qinghai University because of "abdominal distension for 3 months, aggravated with abdominal pain for 1 week". Upon admission, the blood pressure was 150/80 mmHg, pulse rate was 68 bpm, and the SpO2 96%. The patient had a history of abdominal pain for 3 months, which was distended in nature and had intermittent attacks. The above symptoms were significantly worsened 7 days ago, accompanied by difficulty in eating. The color Doppler ultrasound on the abdomen in our hospital showed that the right iliac fossa mixed echo mass. No significant weight gain or loss during the disease.
Physical examination showed that the abdomen is distended, the lower abdomen can be palpable with a mass of about 10 cm in diameter, no abdominal muscle tension, light tenderness in the whole abdomen, obvious at the lower abdomen, but no rebound pain. The patient underwent a total hysterectomy 9 years ago and thyroidectomy 8 years ago both in our hospital, and the past medical history was normal. The patient denied any family history of tumors. Admission blood tests Included WBC12.69 × 109/L,Percentage of neutrophils 86.9%,Lymphocyte 0.63 × 109/L,Albumin 31.8 g/L,Glucose 10.2 mmol/L.Pelvic CT + MRI showed an Massive mixed-density foci at the entrance of the pelvis seems to be a liposarcoma;Fatty lesions in the lower abdomen and pelvis are considered malignant, and liposarcoma may invade the sigmoid colon (Fig. 1a,b,c).
After excluding relevant surgical contraindications, Surgery which included pelvic mass resection + partial colectomy + enterotomy under general anesthesia was performed on August 17, 2020. During the operation, the peritoneum and omentum are swollen, pelvic cavity closed, separated adhesions, a lump about 15 × 10 × 10 cm3 in size can be touched, fixed on the pelvic floor, containing about 500 ml of purulent fluid, unclear borders, adhesion with the posterior peritoneum, rectum, and part of the sigmoid colon close(Fig. 2a). When separate the adhesion between the intestine and the mass, the sigmoid colon appears to be ruptured, then carefully separate the adhesions, free the sigmoid colon, clamp and cut the purse string, end-to-end stapler anastomosis to the distal end, remove the ruptured intestinal tube, use a cutting stapler to make the left abdominal wall at the proximal end Ostomy (Fig. 2b).Use the ultrasonic scalpel to separates the adhesions along the edge of the tumor and removes the tumor completely (Fig. 2c).
Histopathology showed: macroscopic view: a pile of grayish pink irregularly shredded tissue, with a total volume of 18.5 × 14.5 × 7.0 cm. The multi-faceted incision and the cut surface has Fine texture. A section of the excised intestine is 6.5 cm long, Excise a section of intestine with a length of 6.5 cm, with circumferences of 2.5 cm and 2.0 cm at both ends.no obvious masses and nodules were seen in the intestinal mucosa, and a 5 × 3 × 2 cm hard zone was seen on the serosal surface of the intestine. Pathological diagnosis: Combined with immunohistochemistry, it is consistent with dedifferentiated liposarcoma with extensive necrosis; chronic inflammation of colonic mucosa, tumor invasion can be seen under the serous membrane. Immunohistochemical results: S100 (-), STAT6 (-), SMA (-), Des (partially weak +), CD34 (weak +), CD31 (vascular +), FIi-1 (partial +), Ki67 (50%), P53 (-), CDK4 (+), CD117 (-), Dog-1 (-), ER (-), MDM2 (+) (Fig. 4).
This disease needs to be differentiated from gastrointestinal stromal tumor and angiosarcoma. Immunohistochemical examination: immunohistochemical staining showed positive reaction of MDM2, CDK4, Ki67 (Fig. 4). This result confirmed the histological diagnosis of dedifferentiated liposarcoma.