An Extraordinarily Huge Retroperitoneal liposarcoma: A Case Report and Literature Review
Ting-Yao Cheng1, Bo-Han Chen1, Ching-Hen Ting2, Allen W. Chiu1,3
Department of 1Urology and 2Pathology, MacKay Memorial Hospital, Taipei, Taiwan
3School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan
Primary retroperitoneal liposarcoma are rare neoplasm with locally aggressive malignancy. While liposarcoma are thought to originate from adipose tissue, liposarcoma can grow from any region where fat is present. Among all parts of body, retroperitoneal cavity accounts for about 35% to 45%. [3, 4] Symptoms of liposarcoma are usually not obvious and not specific, as result, the time of diagnosis are usually late and the tumor size have become extremely large. Complete surgical resection is the gold standard treatment to liposarcoma. Here, we share our experience of surgical resection of an extraordinarily huge retroperitoneal liposarcoma with multiple local organs invasion.
A 68-year-old male came to our outpatient clinic with the chief complaint of central obesity for a year. He had chronic disease history of hypertension and diabetes mellitus with medication control stably for about 10 years. To lose weight, he went to Chinese Medicine clinic first 2 months ago. However, his body weight kept unchanged after the treatment course. Instead, his abdominal girth increased while muscular atrophy was noted at his four limbs although he did not take any steroid. He denied abdominal or flank pain, tenderness, bowel habit change or tarry stool. Later, he went to the department of Gastroenterology and abdominal echogram showed mass lesion in abdominal cavity. Neither jaundice nor massive ascites was found. Further computer tomography image revealed huge retroperitoneal tumor with multiple surrounding organs displacement, which was caused by extrusion of the giant mass. (Figure 1).
Under the impression of large liposarcoma with multiple organs compression, he was admitted for tumor wide excision by laparotomy. During the operation, a midline incision about 30 cm in length was made and carried down to the fascia. The fascia was incised sharply and the muscles were divided with electrocuting along the direction of the wound incision. The underlying peritoneum was then opened carefully. The intra-peritoneal organs were checked. No tumor seeding or carcinomatosis was noted. After clear dissection of the white line of the hepatic flexure, we saw the huge tumor occupied right abdomen up from diaphragm down to the pelvic cavity with several tight adhesions around inferior vena cava and liver. The space in between the mesocolon and the Gerota's fascia was dissected. The right kidney was embedded by the huge tumor. The solid mass then isolated and dissected free from the surrounding structures. Right renal pedicle was identified and the feeding vessels including renal vein was ligated by the Endo GIA™ Universal Staplers (size: 4.5 cm linear length and 2.5 mm wide, Medtronic, Minneapolis, United States of America) and LigaSure™ (Medtronic, Minneapolis, United States of America). Suprarenal inferior vena cava was wrapped by the tumor while severe adhesion between tumor and diaphragm were noted. With the help of general, thoracic and cardiovascular surgeons, tumor was separated from right liver and diaphragm. Short hepatic vein was repaired with prolene suture and a 24 French chest tube was inserted for the laceration of diaphragm. After hemostasis was secured, another channel drain was inserted at subhepatic space and the muscle and fascia were closed layer by layer. The patient was sent to intensive care unit (ICU) for postoperative care. Estimated blood loss was 7500ml and blood transfusion was given during the operation. After admission to ICU for 3 days, he became stable and was transferred to ordinary ward. Chest tube and wound stiches were removed at postoperative day 5 and day 10. He was discharged from hospital at postoperative day 14 without complications.
The resected specimen was measured 38*28*18 cm in size (Figure 2) and with an attached kidney and a segment of ureter. The tumor cells were positive in CDK4, focal positive in MDM2 (Figure 3) and negative in SMA, S-100. Dense infiltration of CD138 positive, Lambda positive and Kappa negative plasma cells were also found under microscope. The morphology and immunoprofile was consistent with atypical lipomatous tumor/well-differentiated liposarcoma, inflammatory subtype.
His body weight dropped 22 kilograms comparing to the preoperative body weight. The was no evidence of tumor recurrence at outpatient clinic follow up 2 months postoperatively. However, due to the high recurrence rate of this tumor, we arranged to close follow up this patient at outpatient clinic once in a month.
Liposarcoma is the most common malignancy in retroperieoneal soft tissue. The dignosis of primary retroperitoneal liposarcoma is usually delayed because of the related symptoms are trifling and prone to be neglected by patients or even physicians. Since the late detection, the tumors are often large in size at the time they are found. Complete surgical resection is the treatment of choice for retroperitoneal liposarcoma regardless of size. 
Liposarcoma is classified into five categories including myxoid, welldifferentiated, round cell, dedifferentiated and pleomorphic type according to its morphology. Whether the tumor is resected completely or not may influence the prognosis of this disease a lot. However, complete resection of these gigantic tumors are often challenged for surgeons. Huge retroperitoneal liposarcoma often direct invade or compress adjacent organs. To dealing with the adhesion and organ invasion, urologists may need the help from other surgeons, such as cardiothoracic surgeons and gastrointestinal surgeons. Well-differentiated liposarcoma are surgically amenable without recur after complete excision with a clear margin. For this reason, multidisciplinary operation with radical multivisceral excisions with are recommended and would improve the outcome of the patients.
In conclusion, surgical resection seems to be the only chance to treat the aggressive liposarcoma. Complete surgical negative margin would be the key determined the prognosis of liposarcoma. As a responsive surgeon, we should not hesitate to seek for help from other specialists when dealing with surrounding organs, such as diaphragm, liver and vena cava.
1. Yang J, Zhao Y, Zheng CH, Wang Q, Pang XY, Wang T, Ma JJ: Huge retroperitoneal liposarcoma with renal involvement requires nephrectomy: A case report and literature review. Mol Clin Oncol 2016, 5(5):607-609.
2. Akhoondinasab MR, Omranifard M: Huge retroperitoneal liposarcoma. J Res Med Sci 2011, 16(4):565-567.
3. Chen J, Hang Y, Gao Q, Huang X: Surgical Diagnosis and Treatment of Primary Retroperitoneal Liposarcoma. Frontiers in Surgery 2021, 8.
4. Wang S, Han X, Liu S, Xu G, Li J: Primary retroperitoneal liposarcoma: a rare case report. Journal of International Medical Research 2021, 49(12):03000605211063085.
5. Tanaka M, Kawahara T, Nishikoshi T, Hagiwara M, Imai K, Hasegawa K, Koya A, Matsuno N, Takei H, Azuma N et al: Successful surgical treatment for huge retroperitoneal liposarcoma involving the pancreas, right kidney, abdominal aorta and inferior vena cava. Journal of Surgical Case Reports 2017, 2017(11).
6. Han HH, Choi KH, Kim DS, Jeong WJ, Yang SC, Jang SJ, Choi JJ, Han WK: Retroperitoneal Giant Liposarcoma. Korean J Urol 2010, 51(8):579-582.
7. Arakawa Y, Yoshioka K, Kamo H, Kawano K, Yamaguchi T, Sumise Y, Okitsu N, Ikeyama S, Morimoto K, Nakai Y et al: Huge retroperitoneal dedifferentiated liposarcoma presented as acute pancreatitis: Report of a case. The Journal of Medical Investigation 2013, 60(1.2):164-168.
8. Moyon FX, Moyon MA, Tufiño JF, Yu A, Mafla OL, Molina GA: Massive retroperitoneal dedifferentiated liposarcoma in a young patient. Journal of Surgical Case Reports 2018, 2018(10).