A Research of Soft Tissue Lipoma Genesis Factor With Immunohistochemical Analysis

Abstract

Introduction: Lipoma is the most familiar soft-tissue tumor. But the etiology of lipoma remains imprecise. Sex steroid hormones such as estrogen have effects on muscle and adipose tissue development. There is now significant evidence that sex steroids are involved in the site specificities of adipose tissue metabolism. This association of adipose tissue metabolism between sex steroid hormones suggests a possible role for sex steroids in the pathogenesis of lipoma. Methods: To investigate this concept, the authors evaluated the expression of the estrogen receptor (ER) and the progesterone receptor (PR) in soft tissue lipoma in this study. In addition, angiogenesis and the production of angiogenic factors are fundamental for tumor progression in the form of growth, invasion, and metastasis. Epidermal growth factor receptor (EGFR) is involved in a signaling cascade that influences proliferation and other tumor- promoting activities. In this respect, the authors tried to define the correlation of soft tissue lipoma tumor cell and specific 2 immunohistologic markers, vascular endothelial growth factor (VEGF) and EGFR. The study population included patients who diagnosed with soft tissue lipoma, 20 independent patients were selected. All specimens were stained with hematoxylin and eosin. All slides were examined by a pathologist under a microscope. ER, PR, VEGF, and EGFR expression was analyzed by immunohistochemistry. Result: ER, PR, and EGFR of tumor cell had significantly more negative than positive. And VEGF of tumor cell had significantly more positive than negative. There was no significantly difference between site of tumor and immunohistochemical stain. Discussion and Conclusion: There are only a few studies for ER and PR in soft tissue related tumors. The authors estimated that the abnormal local proliferation and accumulation of adipocyte in soft tissue lipoma is related to sex steroid hormone action, especially estrogen and progesterone. But ER and PR of tumor cell had significantly more negative than positive in this study. The authors concluded that estrogen and progesterone are not impact factor of pathogenesis of soft tissue lipoma. Vascular endothelial growth factor of tumor cell had significantly more positive than negative. Angiogenesis is an essential factor for tumor growth. The VEGF expression of soft tissue lipoma can be understood in the same context. The authors need more study to reveal an association between lipoma and EGFR, because some patients of lipoma were positive to EGFR in this study.