|Year : 2017 | Volume
| Issue : 2 | Page : 193-197
Huge retroperitoneal liposarcoma: a case report and review of literature
Basel Refky1, Mohamed Abdelkhalek MSc 1, Mohamed Zuhdy1, Khaled Gaballa1, Mohammad Arafa2, Khadega Mohamed Ali2, Amr Hany Metwally3, Basma Gadelhak4, Waleed Elnahasa1
1 Surgical Oncology Department, Oncology Center, Mansoura University Hospitals, Mansoura, Egypt
2 Pathology Department, Mansoura University Hospitals, Mansoura, Egypt
3 Intern Physician, Mansoura University Hospitals, Mansoura, Egypt
4 Radiology Department, Mansoura University, Mansoura, Egypt
|Date of Submission||05-Sep-2016|
|Date of Acceptance||05-Nov-2016|
|Date of Web Publication||13-Apr-2017|
Surgical Oncology Department, Oncology Center, Mansoura University, Mansoura, 35516
Source of Support: None, Conflict of Interest: None
Liposarcoma is the most common malignant tumor of the retroperitoneum. We report a case of huge retroperitoneal liposarcoma weighing 44 kg that was successfully resected.
A 53-year-old Egyptian male patient was presented to our department with progressive abdominal enlargement. Computed tomography scans of the chest, the abdomen, and the pelvis revealed a huge pelviabdominal mass highly suggestive of liposarcoma. Abdominal exploration was performed with resection of a huge retroperitoneal mass weighing 44 kg that was proven pathologically to be liposarcoma.
Despite the huge size of retroperitoneal liposarcomas, they can be surgically resected successfully.
Keywords: liposarcoma, retroperitoneal, sarcoma
|How to cite this article:|
Refky B, Abdelkhalek M, Zuhdy M, Gaballa K, Arafa M, Ali KM, Metwally AH, Gadelhak B, Elnahasa W. Huge retroperitoneal liposarcoma: a case report and review of literature. Egypt J Surg 2017;36:193-7
|How to cite this URL:|
Refky B, Abdelkhalek M, Zuhdy M, Gaballa K, Arafa M, Ali KM, Metwally AH, Gadelhak B, Elnahasa W. Huge retroperitoneal liposarcoma: a case report and review of literature. Egypt J Surg [serial online] 2017 [cited 2017 Aug 18];36:193-7. Available from: http://www.ejs.eg.net/text.asp?2017/36/2/193/204522
| Introduction|| |
Liposarcoma is considered the most common pathological type of soft tissue sarcoma that affects adults. Retroperitoneal liposarcoma may vary in weight and size reaching up to 20 kg, which is rarely reported, and is considered to be a ‘giant liposarcoma’. Here, we report our experience of a giant retroperitoneal liposarcoma that weighed 44 kg and caused marked abdominal swelling, marked leg edema, and respiratory distress .
| Case report|| |
A 53-year-old male patient complained of progressive abdominal enlargement for ∼10 months. When he sought medical advice, an ultrasound scan (US) of the pelvis and the abdomen revealed a large well-defined lobulated pelviabdominal mass that measured ∼15×15 cm. According to that pattern, the US report suspected angiomyolipoma; therefore, a computerized tomographic (CT) scan on the chest, the abdomen, and the pelvis was performed looking for possible metastases and more accurate imaging of the tumor. The CT revealed a large pelviabdominal mass with enhancing soft tissue component inside that was displacing the intestinal loops highly suggesting liposarcoma as the type of the tumor ([Figure 1]). An US-guided biopsy was performed, which was nonrepresentative.
|Figure 1 Computed tomography (CT) scan of the patient’s abdomen and pelvis. CT scan revealed a large pelviabdominal mass with enhancing soft tissue component inside displacing the intestinal loops.|
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After these investigations were done, the patient was referred to the Oncology Center of Mansoura University (OCMU). A CT-guided biopsy was performed, and the result was highly suggestive of liposarcoma. Then abdominal exploration was performed in October 2014. In the operation, we visualized multiple intra-abdominal and retroperitoneal huge masses. We dissected all these masses and did a limited resection anastomosis of a part of the small intestine that was stretched by one of the masses. We also dissected another mass from the descending colon and the left ureter intact ([Figure 2]).
|Figure 2 Patient pictures in the operating room (OR). (a) A picture before the skin incision. (b) A picture after the resection of the mass before skin closure.|
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On postoperative follow-up, the patient’s condition was stable, and the laboratory investigation findings were normal. The patient was discharged 5 days after the operation.
The pathology report confirmed that the tumor was dedifferentiated liposarcoma. The resected specimens weighed 44 kg, making this tumor nearly one of the biggest reported resected liposarcomas in the world ([Figure 3]).
Microscopically, the lesions consist of areas of atypical lipomatous neoplasm/well-differentiated liposarcoma and a nonlipogenic (dedifferentiated) component. The interface between the two zones is abrupt, although in some regions there is a gradual transition between the two components. The areas of well-differentiated liposarcoma consist of typical lipoblasts having hyperchromatic indented nucleus and vacuolated cytoplasm, whereas the dedifferentiated zones are formed of spindle-shaped cells that show hyperchromatic nuclei, scanty cytoplasm with indistinct cell borders, and separated by interwoven collagen fibers. These cells show moderate degree of pleomorphism with few scattered mitotic figures. There are multinucleated giant cells and giant cells of bizarre size admixed with inflammatory cellular infiltrate. Foci of divergent rhabdomyosarcomatous and leiomyosarcomatous differentiation are also present. Moreover, wide areas of necrosis are detected ([Figure 4]).
|Figure 4 Histological features of dedifferentiated liposarcoma. (a) Areas of well-differentiated liposarcoma H&E: ×100, with numerous lipoblasts. (b) H&E: ×400. (c) Areas of dedifferentiated liposarcoma H&E: ×100, with scattered bizarre giant cells and mitosis. (d) H&E: ×40.|
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The most common problem in the differential diagnosis is distinguishing between a pleomorphic sarcoma infiltrating the fat and a dedifferentiated liposarcoma. The presence of clear-cut evidence of atypical lipomatous neoplasm/well-differentiated liposarcoma some distance away from the dedifferentiated areas helps in the diagnosis of dedifferentiated liposarcoma.
Long-term follow-up and regular radiological scans were done on the patient looking for recurrence and survival.
Review of the literature
Liposarcoma is the most common type of soft tissue sarcoma that is encountered in 10–20% of all cases. It affects both sexes equally, with a peak age group of 40–60 years . There are four histological subtypes of liposarcoma: well differentiated, undifferentiated, pleomorphic, and myxoid .
Several factors have been reported to affect the prognosis, namely, the histological subtype, tumor site, and the completeness of surgical resection. As an example, the overall 5-year survival rate is reported to reach 88–100% in myxoid and well-differentiated types. Moreover, the primary cutaneous liposarcoma has an indolent course with subsequently better prognosis, whereas deep high-grade sarcomas are reported to have a 5-year overall survival (OS) of ∼50% .
Unfortunately, the myxoid and well-differentiated types are not well circumscribed and are accompanied by higher risk of local recurrence, particularly with incomplete surgical excision. This eventually leads to differentiation into higher grades and higher risk of metastases, which are more commonly encountered in the lungs followed by the liver .
The risk of local recurrence and distant metastases is higher in both poorly differentiated and round cell types with a reported 5-year OS rate of 50%. The OS rate of dedifferentiated liposarcoma reaches up to 75%, whereas it varies from 30–50% in the pleomorphic subtype depending on the tumor location .
Retroperitoneal liposarcoma has worse prognosis than limb liposarcoma; this can be attributed to the difficulty of attaining negative margins by surgical resection, as it is poorly circumscribed. As a consequence, retroperitoneal liposarcoma tends to recur more frequently and even may lead to death. It is commonly of large size (>10 cm) owing to the capacious potential space of the retroperitoneum .
CT and MRI remain the gold standard imaging tools in diagnosis of liposarcoma. On the contrary, ultrasonography is more commonly used during the follow-up period to detect any recurrence, which is more encountered in pleomorphic types than in the well-differentiated types .
CT reveals liposarcoma as a large space-occupying lesion that displaces or compresses the surrounding organs with a negative attenuation coefficient and sometimes internal septations. Well-differentiated liposarcomas appear mainly hypodense, whereas pleomorphic liposarcomas are heterogenous .
Under MRI, liposarcoma appears as a mass with a thick peripheral ring and linear septae with internal nodules and preserved contiguous structures. Well-differentiated liposarcomas have the same signal intensity as that of the subcutaneous fatty tissue. It is mainly formed of fat, thin or thick fibrous septae − that mainly appears hypointense in T1-weighed images − and intrinsic nodules. After intravenous contrast administration, no significant enhancement is noticed, and only a weak signal increase is detected compared with the unenhanced phase, which is better visualized in the fat-suppressed sequences. The myxoid type appears isodense compared with the muscles in MRI sequences. In the unenhanced phase, it appears mainly cystic. However, after intravenous contrast administration, it shows solid heterogenous pattern, where some areas show no enhancement, which corresponds histologically to areas of mucin accumulation, and other areas appear more enhanced, which corresponds to areas of more cellular aggregation. The pleomorphic subtype appears heterogenous in T1 and T2 sequences owing to poor adipose content. Areas of hemorrhage and necrosis are mainly encountered. It is hypointense compared with fatty tissue in T1 sequences, whereas in T2 sequences, it appears hyperintense with heterogenous internal structure .
Risk assessment in patients with liposarcoma depends mainly on tumor grade and subtype. However, the tumor standardized uptake value obtained by positron emission tomography before any intervention was found to be a more useful parameter for risk assessment than tumor grade and subtype. Reduced survival and increased risk of early recurrence and distant metastasis were reported with SUV greater than 3.6 .
Biopsy is the gold standard diagnostic procedure for liposarcoma. Excisional biopsy is recommended for small, superficial, fatty tumors, whereas in case of deep large tumors (>3 cm), open incisional biopsy followed by definitive resection is the procedure of choice .
Surgery with or without radiotherapy remains the mainstay of treatment of liposarcoma. Moreover, there may be also a role for chemotherapy. Myxoid liposarcoma was found to be the most chemosensitive histological type, whereas well-differentiated and dedifferentiated types are less sensitive to chemotherapy. Multimodality treatment − including chemotherapy and radiotherapy − is the most effective in case of high-grade liposarcoma. Surgical resection should be done with wide safety margins to minimize the risk of recurrence and dedifferentiation. This could be challenging in some cases, as it could be hard to differentiate between the tumor and retroperitoneal fat. Moreover, it may be difficult to resect any adjacent organs. Achievement of complete surgical resection can be sufficient alone to obtain satisfactory outcomes. This can minimize the need for postoperative radiotherapy, that too which is mainly applied in large doses and fields owing to the size and location of liposarcoma ,.
Huge retroperitoneal liposarcomas have been reported many times in literature. In 2007, Haber et al. reported a giant retroperitoneal liposarcoma that weighed 10.7 kg and involved the descending colon in a 37-year-old male patient. Complete surgical resection and partial colectomy were done, and pathological examination revealed well-differentiated liposarcoma .
Hashimoto et al., in 2010, reported a case of a 41-year-old male patient with huge retroperitoneal liposarcoma that was related to the right kidney. Complete surgical resection with scarification of the right kidney was done. Pathological examination revealed dedifferentiated liposarcoma and the specimen weighed 22 kg .
In 2011, Akhoondinasab and Omranifard reported complete surgical resection of a giant retroperitoneal liposarcoma in a 54-year-old male patient. The mass was dissected from the aorta, kidneys, and ureters and was excised en bloc. It weighed 32 kg, and pathological examination revealed a well-differentiated type .
Saini and Kapoor in 2012 reported a huge retroperitoneal liposarcoma in a 65-year-old male patient. It measured 54×43×38 cm3 and was infiltrating the descending and sigmoid colon. Complete surgical resection and partial colectomy were done with an end colostomy procedure. Pathological examination revealed myxoid liposarcoma with areas of dedifferentiation, and the mass weighed 41 kg . In 2015, Caizonne et al. reported a giant retroperitoneal liposarcoma in a 64-year-old female patient. She complained of progressive abdominal enlargement. CT scan of the abdomen and pelvis revealed a huge retroperitoneal mass that measured 42×37×18 cm3 and extended from the subhepatic area to the pelvis displacing the right kidney to the left. Pathological examination revealed a pleomorphic liposarcoma with areas of myxoid changes originating from the perinephric fat of the right kidney and infiltrating the periureteral tissue .
| Conclusion|| |
The mainstay of treatment of retroperitoneal liposarcoma is complete surgical resection even in huge ones whenever possible.
Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the editor in chief of this journal.
W.N., B.R., M.A. and M.Z. performed the surgery and follow up. K.G., A.H., M.A., K.A. and B.G. were responsible for conception of the idea, overall preparation and revision of the manuscript. All authors read and approved the final manuscript.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]