Retroperitoneal and scrotal giant liposarcoma: report of a case

Giant retroperitoneal well differentiated liposarcoma: A case report and literature review

INTRODUCTION AND IMPORTANCE

The most prevalent type of primary retroperitoneal tumors is soft tissue sarcoma (STS). Liposarcoma accounts for 40 % of retroperitoneal tumors (Mack, 1995). Retroperitoneal liposarcoma accounts for 12 % to 40 % of all liposarcomas (Vijay and Ram, 2015). They typically present with advanced disease and often carry a poor prognosis. Because of their rarity and anatomic location, these malignant tumors can cause a diagnostic dilemma and present several therapeutic challenges (Vijay and Ram, 2015).

CASE PRESENTATION

A 48-year-old male patient presented to our gastrointestinal oncology clinic with a 2-year history of abdominal discomfort, weight loss and steadily growing abdominal swelling. A soft, rubbery lobulated mass with a positive "slippage sign" was palpable over all the quadrants of the abdomen. CT scan conclusion was retroperitoneal lipoma with internal enhancing nodular components. During laparotomy, a fatty mass measuring 55*60*22 cm and weighing 14 kg was excised. Histopathologic report showed a well differentiated liposarcoma (WDLS).

CLINICAL DISCUSSION

Giant retroperitoneal liposarcoma (RPL) is exceedingly rare. Liposarcomas have diverse MRI and CT appearances due to the various subtypes. WDLS are difficult to identify from lipomas before surgery. Histopathology is the only way to provide a reliable diagnosis; therefore en block resection is the recommended approach when malignancy cannot be ruled out.

CONCLUSION

Although imaging with ultrasound, CT, and MRI can aid in the diagnosis, differentiating WDLS from lipoma pre-operatively can be difficult, and en block resection is the recommended approach when malignancy cannot be ruled out.

Special clinical scenarios in RPS: Involvement of great vessels and pancreas and penetration across natural foramina

The primary treatment for retroperitoneal sarcomas is surgery. This requires a carefully planned, typically multivisceral, resection. A few complex scenarios that may arise include vascular involvement, pancreatic involvement, or herniation of the tumor into another compartment outside of the retroperitoneum. These scenarios must be anticipated before surgery to optimize preoperative preparation, minimize postoperative morbidity and mortality, and improve oncologic outcomes. Our aim is to highlight these clinically challenging anatomic presentations that can be encountered in patients with retroperitoneal sarcomas.

Giant Retroperitoneal Liposarcoma: Correlation Between Size and Risk for Recurrence

Soft tissue sarcomas (STSs) are rare tumors that represent almost 1% of adult malignant tumors. The annual incidence rate for such tumors is 2 - 5/100,000 population. The most common type of STS in adults is liposarcoma, which represents 15-20% of adult STSs. It is of mesodermic origin derived from adipose tissues, and known as the most common primary malignant tumor of the retroperitoneum. Other sites of involvement include the extremities, trunk and to a lesser extent the pleural cavity, esophagus, mediastinum and others. Due to the potential large retroperitoneal space, retroperitoneal liposarcoma (RPL) is usually asymptomatic during the initial phase, developing symptoms at a late stage due to large mass compressing nearby retroperitoneal structures. The average diameter and weight of RPL during diagnosis is 20 - 25 cm and 15 - 20 kg, respectively. Several factors were labelled as risk factors for recurrence, such as histological type, tumor grade, age, resectability and tumor size. Controversy exists regarding the relationship between tumor size and recurrence rate, thus, tumor size as a risk factor for recurrence should be clarified. Although there is no consensus regarding the precise definition of giant RPL, it is defined by several literatures as an RPL of greater than 30 cm in diameter or with weight of more than 20 kg. The main purpose of this article is to review the current English literature regarding giant RPL and examine the relationship between tumor size and risk for recurrence.

Retroperitoneal Liposarcoma: The Giant Type

Retroperitoneal tumors (RPTs) are very rare tumors that arise in the large space of the retroperitoneum. About two-third of these tumors are malignant, of which soft tissue sarcoma (STS) is the most common and comprises almost one-third of malignant RPTs. Twenty to thirty percent of RPTs are benign. The retroperitoneal cavity has a very large potential space for tumor enlargement to a very high diameters without causing specific symptoms, especially during the initial phase of tumor enlargement. On diagnosis, the average tumor weight is 15 - 20 kg and tumor diameter is 20 - 25 cm. The most common retroperitoneal sarcoma type is liposarcoma, which account for 20% of all sarcoma types and 40% of all retroperitoneal sarcomas (RPSs). Other less common STS arise in the retroperitoneum include leiomyosarcoma and undifferentiated pleomorphic type. Giant liposarcoma is usually defined either as tumor diameter of 30 cm or more or tumor weight of 20 kg or higher. This specific type of sarcoma is very uncommon, with few case reports published in the English literature. Herein, we present a case of a healthy 33-year-old male patient, who was admitted due to abdominal distension and increased body weight since few months. An abdominopelvic computed tomography (CT) scan demonstrated a giant retroperitoneal mass of almost 40 cm in diameter in its largest dimension, located in the right retroperitoneal space. Ultrasound (US)-guided fine needle biopsy (FNB) was consistent with well differentiated liposarcoma. Surgical resection of the tumor along with the right colon, right ureter and kidney, third and fourth duodenal parts and part of the right iliopsoas muscle was contemplated. Histopathological report revealed well-differentiated liposarcoma of 50 cm in diameter, with foci of dedifferentiation, presented by pleomorphic sarcoma. Surgical margins were microscopically negative.

Surgical Diagnosis and Treatment of Primary Retroperitoneal Liposarcoma

Background: Primary retroperitoneal liposarcoma (PRPLS) is the most common soft tissue sarcoma of the retroperitoneum with high recurrence rate and short overall survival (OS).

Methods: A retrospective review of 51 patients with PRPLS, treated between September 1, 2009 and November 30, 2020, was conducted to evaluate clinical outcomes of PRPLS resection. Patient demographics, histopathologic subtypes, overall survival (OS), progression-free survival (PFS), disease recurrence rate, and tumor stage were reviewed and analyzed. Univariate analysis was done to identify factors potentially affecting OS and PFS of PRPLS patients. Multivariate Cox proportional hazards analysis was used to evaluate the impact of various clinicopathological factors on OS and PFS of PRPLS patients.

Results: Fifty-one PRPLS patients (28 Males, 23 Females; mean age 56.25 years) were evaluated. There was no significant effect of age, gender, contiguous organ resection, degree of differentiation and tumor size on the OS and PFS of the patients. Univariate analysis showed that negative surgical margin and early tumor stage significantly correlated with OS and PFS (all P < 0.001). Multivariate analysis showed that tumor stage [hazard ratio (HR) = 1.177, P = 0.001] was an independent predictors of poor progression-free survival, and surgical margins [HR = 4.0674 P = 0.038] and tumor stage [HR = 1.167 P = 0.001] were identified as independent predictors of poor overall survival.

Conclusion: Negative surgical margin is a prognostic factor of OS, and can prolong the postoperative survival time of PRPLS patients. Tumor stage is a prognostic factor for OS and PFS, and can influence the survival of PRPLS patients. Earlier tumor stages of PRPLS are associated with significantly better outcomes.

Giant recurrent liposarcoma of the retroperitoneum - A surgical challenge: A case report

INTRODUCTION

Sarcomas are a rare entity with heterogeneous clinical behavior. We herein present the case of a giant retroperitoneal dedifferentiated liposarcoma and aim to remind the clinical, histological, and therapeutic features of this rare tumor.

PRESENTATION OF CASE

An 80-year-old patient was complaining of significant abdominoscrotal swelling. On physical examination, a 25-cm swelling extending from the right iliac fossa to scrotums, was observed. CT scan revealed a retroperitoneal fatty mass with necrotic areas. Ultrasonography-guided biopsy was carried. Pathological report demonstrated a dedifferentiated sarcoma. An en bloc resection of the tumor was performed through a right iliac incision extended to the scrotum. After one year of follow up, the patient had a 30-cm local recurrence. After complete resection, the patient died two days after the procedure due to neurological distress.

DISCUSSION

'Giant' liposarcomas over 20kg are extremely rare. CT-Scan and MRI are very useful for defining their size and limits. The resection of a retroperitoneal sarcoma of remarkable size is a challenge for the surgeon owing to the anatomical site that makes it hard to obtain safe margin and to the adherences with the contiguous organs. Dedifferentiated histologic subtypes and negative surgical margins are associated with poor prognosis. This explains the high rate of local recurrence after surgical excision.

CONCLUSION

In rare cases, retroperitoneal dedifferentiated liposarcomas can extend through the inguinal canal to the scrotum. Surgical resection obtaining negative margins, remains the curative treatment that reduces the risk of recurrence. Careful follow-up to detect early recurrence is essential for optimal care.

Giant retroperitoneal liposarcoma with a maximum diameter of 37 cm: a case report and review of literature

Retroperitoneal liposarcoma is a rare malignancy derived from adipocytes. They can grow to large sizes before inducing clinical symptoms. Giant retroperitoneal liposarcoma with a diameter over 30 centimeters is extremely rare. So far, only 13 cases of giant retroperitoneal liposarcoma with a diameter greater than 30 cm have been reported. There is very little experience in the treatment of these bulky tumors. Herein, we report a 65-year-old male patient diagnosed with giant retroperitoneal liposarcoma. The patient underwent successful complete surgical resection. The tumor was found to occupy almost the entire abdominal cavity, measuring 37.0 cm × 32.0 cm × 26.5 cm in size and 21.0 kg in weight. Histopathological analysis indicated a grade I, well-differentiated liposarcoma. The patient was discharged uneventfully, and no sign of recurrence was observed at 12-month follow-up. Moreover, we reviewed 13 literatures in English published on PubMed database regarding retroperitoneal liposarcoma greater than 30 cm in diameter. The analysis suggests that size alone should not be considered as a contraindication to surgical resection. Combined resection of adjacent organs is necessary if local invasion is confirmed. The role of adjuvant radio or chemotherapy remains controversial. Thorough evaluation on the extent of resection should be made to minimize post-surgery decline in quality of life.

Recurrent giant retroperitoneal liposarcoma with 10 years follow up. Case report and review of literature

INTRODUCTION

This case is of a patient with a recurrent giant retroperitoneal liposarcoma, followed-up and operated multiple times over 10 years. We report this case because of its rarity and review all previous articles reporting "Giant Retroperitoneal Liposarcoma" in the English literature.

CASE DESCRIPTION

A 70 years old man presented to our clinic for dizziness and fatigue. He was incidentally found to have a large retroperitoneal mass filling all the length of the abdominal cavity and shifting all intraabdominal viscera and kidney to the left side. En bloc excision of a 50 × 30 × 18 cm, 9 kg tumor was performed. Final pathology revealed a well-differentiated liposarcoma. Five years later, the patient was reoperated for recurrence and a well-differentiated liposarcoma was excised in 2 pieces (the biggest measuring 14 × 11 × 7 cm) along with the appendix. Four years later the patient was operated on again for a second recurrence, and again a well-differentiated liposarcoma (16 × 10 × 7 cm) extending into the right inguinal canal was excised. One year thereafter, the patient was diagnosed with a third recurrence (22 × 12 cm).

DISCUSSION

Retroperitoneal Liposarcomas are rare tumors, presenting with different histological differentiation. They are diagnosed using multiple imaging modality, mainly CT scan, and it is confirmed by percutaneous large core needle biopsy. R0 Surgical excision remains the proper treatment for non-metastatic tumors, which may necessicate multiorgan resection. They rarely grow to reach a large size and be labled as "Giant Retroperitoneal Liposarcoma".

Usefulness of laparoscopy in the management of incidentally discovered retroperitoneal liposarcoma mimicking inguinal hernia: A case report and literature review

INTRODUCTION

Liposarcomas comprise around 10%-16% of soft tissue sarcomas. The two major sites of liposarcoma are the extremities and retroperitoneum. However, retroperitoneal liposarcomas mimicking inguinal hernia are rare. We present a case of retroperitoneal liposarcoma mimicking inguinal hernia, which was diagnosed after laparoscopic surgery and underwent curative resection.

PRESENTATION OF CASE

A 46-year-old man was admitted to our hospital with a right inguinal pain and swelling that had been recognized for 3 years. We diagnosed the inguinal swelling as a right inguinal hernia and planned laparoscopic surgery for inguinal hernia repair. A hernia sac, however, was not found and swollen retroperitoneal fatty tissue near the right internal inguinal ring was observed by laparoscopy. We aborted the surgical procedure and performed computed tomography and magnetic resonance imaging, which revealed an extraperitoneal and lipomatous tumor extending through the inguinal canal to the scrotum. Wide local excision of the tumor, along with right orchidectomy, was performed under laparotomy. Histopathological diagnosis showed well-differentiated liposarcoma of the retroperitoneum and confirmed tumor-free margins. No evidence of recurrence or metastasis was seen in the 9 months after curative resection.

DISCUSSION AND CONCLUSION

Laparoscopic surgery for inguinal hernia enables to observation of the inguinal region and management of rare cases, such as retroperitoneal liposarcoma.

Retroperitoneal Liposarcoma: A Concern in Inguinal Hernia Repair

Background and Objectives:

The goal of the study was to evaluate retroperitoneal sarcomas with continuous growth into the scrotum through the inguinal canal with regard to diagnostic approach, surgical treatment, and outcome. The analysis is based on a comprehensively documented case and a complete systematic review of published literature. Potential pitfalls are highlighted.

Methods:

We describe the case of a 57-year-old male Caucasian who presented with a swelling in the right groin. Suspecting a scrotal hernia, transabdominal preperitoneal plasty surgery was planned but intraoperatively a large retroperitoneal mass was revealed. After computed tomography scan and magnetic resonance imaging, a complete resection of the tumor was performed. Ten previously published cases describing the same pathology were retrieved from the PubMed database and analyzed systematically in a complete literature review.

Results:

Histology showed a well-differentiated liposarcoma with tumor-free resection margins. Twenty-two months postoperatively, the patient is in complete clinical remission.

Conclusion:

Preoperative clinical suspicion of retroperitoneal involvement is paramount for developing of a surgical strategy and in unclear cases demands extended preoperative diagnostic workup. Following the appropriate patient management is crucial to prognosis.

Comparison of retroperitoneal liposarcoma extending into the inguinal canal and inguinoscrotal liposarcoma

BACKGROUND

This study was designed to analyze differences between retroperitoneal liposarcoma (RLPS) extending into the inguinal canal and inguinoscrotal liposarcoma.

METHODS

We retrospectively reviewed the records for patients who were managed for inguinal liposarcoma at Samsung Medical Center, a tertiary hospital, between January 1998 and December 2016. Patient data on demographics, tumour location, surgery, adjuvant therapy, histology, recurrence and death were collected. We used Mann-Whitney, Fisher exact and Kaplan-Meier log-rank tests to analyze differences between groups.

RESULTS

Seven of 179 (3.9%) patients with abdominal liposarcoma had inguinoscrotal liposarcoma, and 6 of 168 (3.6%) patients with RLPS had extension to the inguinal canal. No differences were observed between groups in sex (p > 0.99), mean age (49.7 ± 6.4 yr v. 52.1 ± 12.5 yr, p = 0.37), laterality (p > 0.99) or scrotal involvement (40.0% v. 66.7%, p = 0.57). The RLPS group had significantly larger tumours than the inguinoscrotal group (27.9 ± 6.8 cm v. 7.8 ± 4.2 cm, p = 0.001). Postoperative complications were significantly more common in the RLPS group (n = 4, 83.3%); patients in the inguinoscrotal group experienced no postoperative complications (p = 0.021). Log-rank tests showed that the groups had no statistical differences in disease-free survival (p = 0.94) or overall survival (p = 0.10). However, inoperable disease-free survival was significantly poorer in the RLPS group (p = 0.010).

CONCLUSION

Although initial signs and symptoms can be similar, RLPS extending into the inguinal canal was associated with significantly higher morbidity and mortality than inguinoscrotal liposarcoma.

Clinicopathological characteristics and experience in the treatment of giant retroperitoneal liposarcoma: A case report and review of the literature

Retroperitoneal liposarcoma (RPLS) is a rare tumor, especailly those over 20 kg that are called "giant liposarcoma," whose characteristics and treatments remain relatively unknown. Herein, we report a giant RPLS measuring 65 × 45 × 30 cm in diameter and 31 kg in weight, which we successfully performed complete excision through interdisciplinary cooperation. The patient had an uneventful postoperative course and was discharged without complications. Afterwards he underwent radiotherapy and had no evidence of tumor recurrence or symptoms of metastasis at 3-month CT scan and 8-month follow-up. We also first review the 13 cases reported in literature published in PubMed regarding giant RPLS. Giant RPLS commonly occurs in adults aged 40-60 y and presents atypical clinical manifestations. CT scan is the most useful examination and preoperative biopsy is controversial. Complete surgical resection still remains the principal treatment. Giant RPLS can also be removed, even reach to R0 excision, by a multidisciplinary team in a specialized center after meticulous planning even though its gigantic tumor size. Local radiotherapy following surgery may improve the rate of recurrence. Besides, closely follow-up and routine examinations are required.

Giant retroperitoneal liposarcoma: Case report and review of the literature

AIM

Retroperitoneal soft-tissue sarcomas are relatively uncommon diseases, the most frequent histotype, ranging from 20% to 45% of all cases, is represented by liposarcoma, which is a hard-to treat condition for its local aggressiveness and clinical aspecificity.

PRESENTATION OF CASE

We report a case of a 64-years-old woman who underwent surgical resection for a giant pleomorphic retroperitoneal liposarcoma.

DISCUSSION

Currently chemotherapy for retroperitoneal soft-tissue sarcomas is no effective, and radiotherapy has limited efficacy due to the toxicity affecting adjacent intra-abdominal structures, showed validity only in case of high-grade malignancy by reducing local recurrence, but with no advantage in overall survival. Nowadays only, the complete surgical resection remains the most important predictor of local recurrence and overall survival.

CONCLUSION

The removal of a retroperitoneal sarcoma of remarkable size is a challenge for the surgeon owing to the anatomical site, to the absence of an anatomically evident vascular-lymphatic peduncle and to the adhesions contracted with the contiguous organs and with the great vessels. Therefore, we believe that, particularly for large-size diseases associated to high-grade malignancy, a complete surgical resection with removal of the contiguous intra and retroperitoneal organs when infiltrated represents the only therapeutic option to obtain a negative margin and therefore an oncological radicality.

Giant retroperitoneal liposarcoma- renal salvage by autotransplantation

Liposarcomas are the most common retroperitoneal soft tissue tumors. We here in report a case of giant retroperitoneal sarcoma which weighed 24 kgs. Renal autotransplant of right kidney was done for organ preservation. The patient has done well after a follow up of 63 months. Complete surgical resection with organ preservation is the goal of treatment in patients with retroperitoneal liposarcomas.

LIPOSARCOMA OF THE KNEE IN A TENNIS PLAYER: CASE REPORT

Liposarcoma is an uncommon malignant tumor. It originates in the mesenchymal cells, and is the most common of the soft tissue sarcomas. The authors report a case of a 40 year-old male tennis player with liposarcoma in the posterior right knee and distal thigh region.

Giant recurrent retroperitoneal liposarcoma presenting as a recurrent inguinal hernia

Retroperitoneal liposarcoma presenting as an inguinal hernia is a rare entity. We present the first case of Giant recurrent liposarcoma presenting as a recurrent inguinal hernia in a 40-year-old male. Physical examination showed an irreducible lump in the right inguinal region and a scar in the right lumbar and right inguinal region. Computed tomography (CT) scan of abdomen revealed it to be a retro peritoneal mass extending into the right inguinal region along and involving the cord structures. Wide local excision of the tumour with right orchidectomy and inguinal hernioplasty was performed. Histo-pathology confirmed it to be a liposarcoma. Patient received postoperative radio therapy. Follow up of two years has shown him to be disease free. Retroperitoneal liposarcoma can grow along cord structures into the inguinal canal and mimic an irreducible indirect inguinal hernia.

Surgical treatment of a giant liposarcoma in a Japanese man

We report a case of a rapidly progressing giant retroperitoneal liposarcoma weighing 22 kg in a 41-year-old Japanese man, successfully treated with surgical excision. To our knowledge, this is the largest liposarcoma in the Japanese population reported in the literature.

Retroperitoneal giant liposarcoma

Retroperitoneal liposarcoma is an infrequent, locally aggressive malignancy. We report two cases of huge retroperitoneal liposarcomas. The presence of a palpable abdominal mass was a common symptom of the two patients. Preoperative imaging study showed huge retroperitoneal tumors. Both patients underwent complete surgical resections, and a negative microscopic margin was achieved in both cases. The histopathologic diagnosis was a well-differentiated retroperitoneal liposarcoma. Neither of the two patients developed a recurring tumor during the 1.5 years of follow-up.

A prospective evaluation of CT features predictive of intra-abdominal hypertension and abdominal compartment syndrome in critically ill surgical patients

AIM

The aim of this study was to validate the computed tomography (CT) features of intra-abdominal hypertension (IAH) by relating them to the clinical measurement of intra-abdominal pressure (IAP) in critically ill surgical patients.

MATERIALS AND METHODS

The intra-vesical pressure was measured to reflect IAP in 24 critically ill patients. CT examinations obtained within 24h of IAP measurement were reviewed and scored independently by two consultant radiologists. Each CT examination was scored for the seven proposed features of IAH. Images obtained during the presence of IAH were compared with those obtained in the absence of IAH.

RESULTS

Forty-eight abdominal CT examinations were evaluated, of which 18 (38%) were obtained in the presence of IAH, whereas eight (17%) were obtained in the presence of abdominal compartment syndrome (ACS). At CT, the round belly sign (RBS) and bowel wall thickening with enhancement (BWTE) were significantly more frequently detected during the presence of IAH than when the IAP was less than 12 mmHg (78 versus 20% of examinations, p<0.001 and 39 versus 3% of examinations, p=0.003, respectively), but only BWTE was significantly associated with the presence of ACS (40 versus 11% of examinations, p=0.047).

CONCLUSION

The presence of RBS and BWTE on CT images of critically ill surgical patients should alert clinicians to the possibility of presence of IAH and ACS, and prompt measurement of the IAP and consideration of suitable interventions.

A case of a large retroperitoneal liposarcoma presenting as an incarcerated inguinal hernia

We report a rare case of retroperitoneal liposarcoma developing within an incarcerated inguinal hernia. A 53-year-old man presented to our hospital with left inguinal mass. Preoperative computed tomography revealed an intraabdominal huge mass, and a clinical diagnosis of liposarcoma. Physical findings except for the inguinal mass and laboratory examination, including tumor markers (CEA, CA19-9), were within normal range. Intraoperatively, the mass was incarcerated in the inguinal canal and involved the left testis. We performed a radical tumor resection, including a left orchiectomy. The resected specimen measured 45 x 30 cm and weighed 7,510 g. Histopathologically, the tumor was diagnosed as a well-differentiated liposarcoma, and originated from retroperitoneum. We did not undergo adjuvant therapy in consideration of histopathological subtype and curable surgical treatment. The patient is well and shows no evidence of recurrence four months after the operation.

Giant retroperitoneal liposarcoma

Liposarcomas are one of the most common soft tissue sarcomas of adulthood. Liposarcomas are remarkable because of their frequently large size. We report a case with an extremely large dedifferentiated liposarcoma that weighed 18 kg. Although it was capsulated and could be excised en bloc, the patient suffered a relapse 9 months later and died 1 year after the operation.

Surgical management of primary and recurrent retroperitoneal liposarcoma

Background

Surgery plays a dominant role in the initial and subsequent treatment of retroperitoneal liposarcoma (RPLS). This study was a review of outcomes of patients treated at the Royal Marsden Hospital.

Methods

Records of all patients who had surgery for RPLS since 1990 were reviewed, with particular attention to local recurrence and disease-specific survival. Patients with primary RPLS and those with recurrent RPLS, who had palliative surgery after a variable number of operations performed elsewhere, were considered separately.

Results

Seventy-two patients had surgery for primary RPLS, over half of whom underwent resection of a contiguous organ to achieve clearance. Follow-up of at least 12 months was available for 58 patients. Thirty-four patients had no evidence of recurrence after median follow-up of 26 (range 12–151) months. Low-grade tumour and macroscopic clearance of tumour were significantly associated with a reduced risk of local recurrence and improved survival. Forty-seven patients had palliative surgery for recurrent RPLS. Median survival from time of last operation to death was 27 (range 0–79) months. Follow-up was to a median of 68 (range 14–261) months.

Conclusion

Patients with low-grade RPLS that has been completely resected at the initial operation have the most favourable prognosis. Palliative resection is worthwhile to treat troublesome symptoms of recurrence

Giant mixed-type perinephric liposarcoma

Retroperitoneal fatty tumours are uncommon occurrences in current urologic practice, the differentials being lipomas, liposarcomas and extra-renal angiomyolipomas (AML). We report an unusual case of a 48-year-old Chinese female who presented with a 6.2 kg giant mixed-type liposarcoma in the left perinephric space, invading into the renal cortex and parenchyma. Extirpative surgery with left radical nephrectomy was performed, and histology confirmed liposarcoma with both myxoid and well-differentiated elements. The patient remains well and disease-free at 6-month follow-up. We review the literature on the diagnosis and management of these perinephric lipomatous lesions. We also discuss the diagnostic dilemma in differentiating such malignancies from benign angiomyolipomas in the perinephric area on conventional radiological imaging, and its direct implications with respect to extent of surgery and renal preservation.

Giant Retroperitoneal Sarcoma: A Case Report and Review of the Management of Retroperitoneal Sarcomas

A 42-year-old man presented with lower abdominal pain and a vague abdominal mass. He underwent resection of a well-differentiated liposarcoma arising from his retroperitoneum measuring 50 cm and weighing 11.7 kg (25.8 lb). This is the second largest retroperitoneal soft-tissue sarcoma (RSTS) that has been reported. Over the last 15 years 1123 patients with RSTS in 25 series have been reported with a mean tumor size of 15.7 cm. RSTS represents 0.10 to 0.15 per cent of all malignancies but 45 per cent of all retroperitoneal tumors. Diagnosis and treatment of RSTS can be extremely challenging for a general surgeon. Symptoms are nonspecific and may occur only after the tumor is very large. Abdominal discomfort is the presenting complaint in 60 to 70 per cent of patients and palpable mass in 70 to 80 per cent. Treatment of RSTS remains surgical. Multiple trials of chemotherapy and radiation therapy show no survival benefit. The only successful treatment of this tumor is complete excision; 51.4 per cent of tumors can be completely excised, and 50.2 per cent of these excisions include adjacent organs. Long-term prognosis without complete excision is grim with average 5- and 10-year survival rates of 16.7 and 8.0 per cent. With aggressive surgical therapy survival is increased to 58.0 and 39.6 per cent.