[Lipoma of the uterus: clinical and ethiopathological approach of 7 cases with immunohistochemical study of histogenesis]

BACKGROUND: Lipoleiomyoma of the uterus (LLU) is an extremely rare, benign, uterine tumour. This rare disease was unknown for a long time. Their histogenesis remains controversial. AIM: To describe the clinical and pathological aspects of uterine lipoleiomyoma and to try to specify, by an immunohistochemical study, its degenerative or tumoral nature. METHODS: 7 cases of LLU were identified represented by 2 pure Lipoma and 5 Lipoleiomyoma. We performed an immunohistochemical study including anti-vimentin, anti-smooth muscle actin, anti PS-100, anti-desmin, anti-factor VIII and anti-HMB- 45. The results were correlated with the pathogenesis of this lesion. RESULTS: Immunohistochemical analysis showed an expression of PS 100 only in lipocytes whereas leiomyomatous cells express only smooth muscle actin. CONCLUSION: Our study supports the benign tumoral nature of the fatty uterine lesions. Lipoleiomyomatous cells may originate from the transformation of a totipotent mesenchymal cell and not from a degenerative process.