A Case of Giant Mesenchymal Uterine Tumor: Lipoleiomyoma.

BACKGROUND Uterine lipoleiomyoma is a rare benign tumor composed of varying proportions of smooth muscle fibers and mature adipocytes, without identification of hemorrhage, necrosis, or cyto-architectural atypia. It is part of the leiomyomas category, with an incidence of 0.03-0.2%. The pathogenesis of this lesional category is still unclear, but there are several theories that could explain the occurrence. Magnetic resonance imaging is the most useful diagnostic imaging method. There are a number of pathologies whose exclusion is necessary, with the differential diagnosis being made mainly based on microscopic examination and completed with immunohistochemical tests. Their treatment, when necessary, is surgical, with an excellent post-therapeutic evolution and prognosis. CASE REPORT We present the case of an elderly, postmenopausal patient who presented with abdominal pain, abnormal vaginal bleeding, and pollakiuria. The associated pathologies of the patient correspond to those mentioned in the literature, the particularities of the case being given by the large size of the tumor and the association with 2 other typical leiomyomas. Immunohistochemical markers used to exclude other diagnoses (desmin, h-caldesmon, S100, calretinin, MDM2, CD34) confirmed the diagnosis of uterine lipoleiomyoma. Because the patient was symptomatic and a large nodular mass was identified by ultrasound, surgical treatment was performed. CONCLUSIONS Although it is a benign lesion with an excellent prognosis, the pathogenetic mechanisms are not fully known. Theories of pathogenesis range from misplacing embryonic adipocytes to connective tissue fatty degeneration, and further studies are needed to establish the origin of this lesion.