Primary adult soft tissue sarcomas represent 1% of all cancers and represent a treatment challenge for surgeons and oncologists. Of these sarcomas, 15% are located in the retroperitoneum. Randomized series that have examined both radiation therapy and chemotherapy have not shown a survival benefit. Conversely, radiotherapy may delay the time to local recurrence but not overall survival. Our review presents medical records of 5 consecutive patients undergoing retroperitoneal sarcoma excision from May 2004 through February 2006. Images were obtained from the patients’ exams and during their surgical procedures. Surgery is the only potential curative treatment as “retroperitoneal surgeons.” Urologists are completely able to approach these kinds of tumors.
BJ Pereira, R Borges, R Leão, V Grenha, H Coelho, A Brandão, P Temido
Submitted April 4, 2012 - Accepted for Publication April 23, 2012
KEYWORDS: Retroperitoneal sarcomas, liposarcoma, angiosarcoma, rhabdomyosarcoma, pararenal mass, retroperitoneal surgery
CITATION: UroToday Int J. 2012 August;5(4):art 35. http://dx.doi.org/10.3834/uij.1944-5784.2012.08.08
Primary adult soft tissue sarcomas represent 1% of all cancers and represent a treatment challenge for surgeons and oncologists . Of these sarcomas, 15% are located in the retroperitoneum. In most surveys, their incidence increases between the fourth and the sixth decade, and there’s a distinct male predominance . Retroperitoneal sarcomas may have diverse histopathology; liposarcomas and leiomyosarcoma are the most common (31 and 24%) [3,4] and their progression depends on the tumor grade, size, and the presence of metastasis. Despite its size, it is often considerably ab initio and the presenting symptoms might be vague and unspecific, including abdominal or lumbar pain or mass, weight loss, gastric repletion sensation, nausea, or vomiting [2,4,5,6,7]. Thus, in about 80% of the cases, retroperitoneal sarcomas may simulate symptoms from contiguous organs or may compromise them (by involvement or invasion) [6,8]. Abdominal computed tomography (CT) is the gold-standard examination for the diagnosis of a retroperitoneal mass . Surgery seems to be the only potentially curative treatment [4,7,9]. However, since retroperitoneal sarcomas are generally large with locally advanced presentation, and are adjacent to vital organs and major vascular structures, complete surgical resection is possible only in 67% of patients presenting with primary disease . Therefore, the outcome is characterized by a high local recurrence rate leading to poor overall survival [7,11]. Distant metastatic dissemination is rare due to poor vascularization . Randomized series that have examined both radiation therapy and chemotherapy have not shown a survival benefit [4,7,9,10]. Conversely, radiotherapy may delay the time to local recurrence but not overall survival .
MATERIALS AND METHODS
Medical records of 5 consecutive patients undergoing retroperitoneal sarcoma excision from May 2004 through February 2006 were reviewed. Images were obtained from the patients’ exams and during their surgical procedures.
Clinical Case 1
JCG, a 48-year-old male, presented with pain and right abdominal swelling, a solitary hydronephrotic right kidney, and a right varicocele. He had a personal history of left renal agenesis, a gastric ulcer, and hyperuricemia. He underwent an abdominal CT that showed a retroperitoneal mass and a right hydronephrotic kidney (Figure 1a, Figure 1b). The first biopsy of the retroperitoneal mass revealed an undetermined soft tissue malignant neoplasm (liposarcoma, myxoma, or other). He underwent a second ultrasonography-guided biopsy that confirmed a well-differentiated liposarcoma. Surgical excision of the retroperitoneal sarcoma on May 2004 confirmed the diagnosis of a well-differentiated sarcoma (217 g), completely removed. The patient died during chemotherapy with doxorubicin. The histopathology showed a neoplastic mass containing adipocytes of variable dimensions (Figure 1c) and a collagenous and myxoid stroma (Figure 1d) beside atypical cells with a pleomorphic nucleus (Figure 1d, Figure 1e).
Clinical Case 2
LJSC, a previously healthy 70-year-old male, presented with pain and a palpable left stony lumbar mass. Renal angiography showed that the mass had fat and was independent from the left kidney (Figure 2a). He was submitted for surgical excision on November of 2004. Pathologic analysis of the retroperitoneal mass (1.026 g; 14 cm x 12 cm x 11 cm) revealed a sarcoma containing fusiform cells in beams (Figure 2b), areas of pleomorphic patterns (Figure 2c), and areas with myxoid configuration (Figure 2d) with a high mytotic index mainly in the pleomorphic area (Figure 2e). There were also some big cells with exocentric nuclei and eosinophilic cytoplasm (Figure 2f). The immunochemistry showed reactivity for antidesmin antibodies (Figure 2g), demonstrating the muscle origin of the mass and permitting the diagnosis of pleomorphic rhabdomyosarcoma. The patient underwent radiation therapy, chemotherapy, and survived 20 months after the surgery. He died with local recurrence of the disease.
Clinical Case 3
ABF, a 72-year-old male, presented with hypertension, anorexia, and weight loss (10 kg in 2 months). He was already submitted to a left radical nephrectomy in 1994 subsequent to renal cell carcinoma. A right retroperitoneal mass was found during the study of his hypertension. The right retroperitoneal mass (17 cm x 16 cm x 15 cm) proved to be a poorly differentiated liposarcoma grafted in a well-differentiated liposarcoma (fusiform type). The patient didn’t receive any adjuvant therapy and survived 15 months after surgery. He died with local recurrence.
Clinical Case 4
JTA, an 84-year-old male, presented with complaints of pain and a palpable right lumbar mass. His magnetic resonance imaging (MRI) revealed a bulky retroperitoneal mass (36 cm x 27 cm x 20 cm) with fat content compatible with a lipoma or liposarcoma (Figure 3a, Figure 3b). The histopathology after the excision (June 2, 2006) of the large retroperitoneal mass (weighing almost 10 kg) (Figure 3c, Figure 3d, Figure 3e, Figure 3f, Figure 3g) confirmed our suspected diagnosis: poor differentiated liposarcoma grafted in a well-differentiated liposarcoma (fusiform type). We had to make a concomitant right nephrectomy. The patient didn’t receive adjuvant therapy and remains alive and disease-free more than 42 months after the surgery at 87 years old.
Clinical Case 5
LSC, a 71-year-old female, presented with a retroperitoneal mass diagnosed by ultrasonography. She had no symptoms. On February 2, 2006 she was submitted to a right retroperitoneal mass excision with concomitant right nephrectomy (Figure 4a, Figure 4b, Figure 4c, Figure 4d). The histopathology revealed a high-grade 1.830 g angiosarcoma (neoplastic mass) with extensive hemorrhage and spindle cell areas (Figure 4e) and epithelioid zones (Figure 4f) There were also multilinked vascular structures forming sinusoids (Figure 4g). The immunohistochemistry showed reactivity to anti-CD31 antibodies (Figure 4h) and confirmed the diagnosis of angiosarcoma. No adjuvant therapy was undertaken and the patient died 3 months after the surgery even though there was a complete removal of the mass.
Patient ages ranged from 48 to 84 years (4 men and 1 woman). Three liposarcomas (one of them 22 pounds, 0.73 ounces), 1 rhabdomyosarcoma, and 1 angiosarcoma were submitted for surgical excision. The diagnosis was incidental in 1 patient while 3 presented with a lumbar mass and the other felt weight loss. Two patients had unilateral kidney due to renal unilateral agenesis and previous radical nephrectomy. Concomitant nephrectomy had to be made in 2 patients. Only 1 patient is still alive and disease-free, 42 months after surgery. Postoperative survival ranged from 3 to 20 months in the deceased patients.
The authors' intent is to highlight a rare disease that may simulate renal parenchymatous masses. This series is in accordance with the up-to-date literature: liposarcoma predominance, unspecific presentation symptoms, common concomitant nephrectomy necessity, and poor prognosis associated with short survival rates. Surgery is the only potential curative treatment as “retroperitoneal surgeons.” Urologists are completely able to approach these kinds of tumors.
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