|LETTER TO THE EDITOR
|Year : 2016 | Volume
| Issue : 1 | Page : 424-426
Mixed type retroperitoneal liposarcoma-combination of myxoid and well-differentiated type
Subrata Pal1, Sanjay Sengupta2, Kingshuk Bose2, Sritanu Jana2
1 Department of Pathology, College of Medicine and Sagore Dutta Hospital, Kolkata, India
2 Department of Pathology, Bankura Sammilani Medical College, Bankura, West Bengal, India
|Date of Web Publication||13-Apr-2016|
Gobindanagar, Kenduadihi, Bankura, West Bengal
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Pal S, Sengupta S, Bose K, Jana S. Mixed type retroperitoneal liposarcoma-combination of myxoid and well-differentiated type. J Can Res Ther 2016;12:424-6
Liposarcomas are malignant adipocytic tumors constituting about 20% of soft tissue sarcomas. Morphologically, these are classified into well-differentiated, de-differentiated, myxoid, round cell, pleomorphic, and mixed type. Mixed type liposarcomas represent combined features of the myxoid/round cell and well-differentiated/de-differentiated liposarcoma or features of the myxoid/round cell/pleomorphic subtype. Mixed type liposarcomas are infrequent occurring in elderly patients preferably in retroperitonium and intraabdominal space. Mixed liposarcomas create conceptual problems in the management protocols due to histological diversity and lack of well-established guidelines.
A 57-year-old lady was admitted in surgery ward with complaints of gradually increasing abdominal girth and diffuses abdominal pain for 2 months associated with the symptoms of anorexia, dyspepsia and weight loss. On abdominal examination, a large solid mass was palpable at right lumber and para-umbilical area. A computed tomography (CT) scan of the abdomen showed a large heterogeneous soft tissue mass present at retroperitoneal area compressing abdominal contents to both flanks [Figure 1] without any invasion.
|Figure 1: Computed tomography of abdomen showing solid heterogeneous mass at retroperitonium|
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All hematological and biochemical tests were unremarkable except mild anemia (hemoglobin - 9.5 gm/dl). Laparotomy was performed, and mass was excised. On gross examination, it was a large, soft and solid mass measuring 30 cm × 22 cm × 18 cm. On cut section, two distinct zones were identified yellowish homogeneous and grayish, tan gelatinous areas separated by thin fibrous tissue [Figure 2]. On microscopy, yellowish areas showed proliferation of adipocytes with occasional presences of uni/multi vacuolated lipoblasts. Sections from tan-colored area revealed admixture of round cells and oval to spindle cells in myxoid stroma and prominent delicate branching blood vessels [Figure 3]. Occasional lipoblasts were found in the myxoid area. The adjoining area of two zones was composed of intervening fibrous tissue separating two different histological variants [Figure 4]. Histopathological diagnosis was mixed type retroperitoneal liposarcoma. The patient was further treated with six cycles of chemotherapy. Clinically, she was disease free after 1 year of follow-up.
|Figure 2: Gross picture of the retroperitoneal mass (cut open) shows two distinct zones in the tumor - one area of yellowish lipomatous area and another area of tan colored myxoid area|
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|Figure 3: Photomicrograph shows many spindle cells and branching delicate blood vessels in the myxoid stroma, typical of myxoid liposarcoma (H and E, ×10 view)|
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|Figure 4: Microscopy shows two heterologous components in the same tumor - an area of atypical lipomatous tumor and another area of myxoid liposarcoma (H and E, ×10 view)|
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Liposarcoma is the most common type of retroperitoneal sarcoma accounting 41% of retroperitoneal malignant mesenchymal tumors. According to recent cytogenetic and immunohistochemical data, liposarcomas are classified into three types - well-differentiated/de-differentiated, myxoid/round cell and pleomorphic subtype. Myxoid liposarcoma is the most common variant though uncommon in retroperitoneal location. In retroperitonium, well-differentiated liposarcoma is the most frequent subtype. Only 5% liposarcomas show an admixture of different histological subtypes in the same tumor. Morphological heterogenecity of mixed type liposarcomas have been explained by different levels of maturation within a single developmental pathway of adipogenesis. Clinical features are due to the compression of adjacent organs. CT scan and magnetic resonance imaging are the best preoperative investigations for evaluation. The histomorphological diversity of a mixed liposarcoma may cause misdiagnosis in cytology and small biopsy. Multiple sections from different parts are necessary to avoid misdiagnosis.
Retroperitoneal liposarcomas have more propensity of local recurrence than distant metastasis. Complete surgical removal with negative marginal status is the cornerstone of favorable prognosis and disease free survival. Sometimes complete surgical removal is difficult and may require resection of involved organs. The role of chemoradiation depends on components, completeness of resection, and differentiation of the tumor. Overall, 5 years survival rate in well-differentiated and myxoid liposarcoma exceeds 70%.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]