Immunohistochemical detection of p53 and MDM2 expressions in liposarcoma with World health organization classification.

BACKGROUND: Liposarcomas are among the most common soft tissue sarcomas in adulthood. AIM: The purpose of the study is to perform a histopathologic typing according to World Health Organization (WHO) classification of cases diagnosed with liposarcoma and to examine the difference of p53 and MDM2 expressions. MATERIALS AND METHODS: The haematoxylin-eosin stained sections of 48 subjects enrolled in the study have been evaluated on the basis of the WHO classification for liposarcoma and sections stained using p53 and MDM2. STATISTICAL ANALYSIS USED: Chi-Square test was applied. RESULTS: 20 subjects were diagnosed with well-differentiated liposarcoma (WLS), 16 myxoid liposarcoma (ML), 7 pleomorphic liposarcoma (PL), and 5 de-differentiated liposarcoma (DLS). The number of cases stained positive with MDM2 and p53 were positive correlated in all subjects (P = 0.02). p53 and MDM2 positivity increased in high grade tumors (P = 0.01). CONCLUSION: p53 and MDM2 immuno-reactivity was found to be potentially useful in liposarcoma diagnosis but a definitive implication would be rather unhealthy due to the small number of cases in our study.

Critical histopathological analysis of 25 dedifferentiated liposarcomas, including uncommon variants, reviewed at a Tertiary Cancer Referral Center.

Background: De-differentiated liposarcomas (DDLSs) are uncommon tumors with a wide histopathological spectrum. Materials and Methods: Over an 8-year period (2003-2011), 25 DDLSs, after review, were critically analyzed for histopathological features. Results: Twenty-five tumors, in 14 men and 11 women (M: F = 1.2:1), with age range of 22-88 years (mean, 53.9), occurred in retroperitoneum (14) (56%), thigh (3) (12%), paratesticular region (3) (12%), chest wall (2) (8%), leg (1) (4%), shoulder (1) (4%), and groin (1) (4%). Tumor size (21 tumors) varied from 7.5 to 25 cm (mean, 17.5). Histopathologically, DD component was high grade in 19 (76%) and low grade in 6 (24%) tumors. Whereas the most common WD component was adipocytic type; the most common DD component was pleomorphic sarcomatous (13) (52%), followed by myxofibrosarcomatous (MFS)-type (6) (24%). Low-grade DD components included MFS (2), fibrosarcoma (2), myogenic/myofibroblastic type (1), and IMFT-type (1). Three tumors displayed meningothelial-like whorls and metaplastic bone formation. Heterologous elements, noted in 11 (44%) tumors, included bone (8) and rhabdomyoblastic differentiation (2). Two tumors displayed homologous differentiation, reinforced with MDM2 staining. S100-P was diffusely positive in WD components (5/7) and focally in DD components (2/9). All patients were treated with surgery, including 10, who underwent adjuvant radiotherapy. Outcomes (16 patients, 64%), over 1-48 months included 10 patients free of disease, 4 died of disease, and 2 patients alive with disease. Conclusions: This study forms the largest documentation of DDLSs, including its wide histopathological spectrum, from our country. Rare cases overlap with pleomorphic liposarcoma. S100-P and MDM2 are useful in substantiating adipocytic differentiation, especially in selected cases. Analysis of adequate tumor sections is vital for correct identification of a DDLS. Surgical excision with adjuvant RT forms optimal treatment.