TY - JOUR T1 - 253 Huge uterine stump (smooth-muscle tumor of uncertain malignant potential) associated with extensive retroperitoneal lymphocystic malformations JF - International Journal of Gynecologic Cancer JO - Int J Gynecol Cancer SP - A108 LP - A108 DO - 10.1136/ijgc-2019-IGCS.253 VL - 29 IS - Suppl 3 AU - N El-Etreby AU - G Fadali AU - K Atta Y1 - 2019/09/01 UR - http://ijgc.bmj.com/content/29/Suppl_3/A108.1.abstract N2 - Objectives Uterine Fibromyomas are the most common benign tumors of the female genital system. But, not all uterine fibroids are completely benign. There is a rather obscure subgroup that may have some grave characteristics such as the ability for recurrence or distant spread. This specific subgroup is called Atypical proliferative myoma by some authors, other authors name it (STUMP) Smooth-muscle Tumor of Uncertain Malignant Potential.We describe the different nomenclatures of these tumors to help identify its ambiguous pathophysiologic characteristics; we also review the different suggested modes of management and report our case with its rare presentation.Methods We report a 49-years-old lady presenting with a huge solid pelviabdominal mass. It was proven to be of uterine origin, and associated with extensive lymphocystic malformations related to the back of the uterus, broad ligament base as well as pelvic and para-aortic retroperitoneal space reaching up to the level of the renal vessels.Results We succeeded to excise the uterine mass and the large lymphocyst. The expert pathologic opinion was in favor of uterine (STUMP). The patient is now nearly 9 months postoperative and her follow-up is completely free. We illustrated the naked-eye as well as the microscopic appearance of this relatively uncommon tumor, and we described the suggested modes of action.Conclusions To our knowledge, this is the first case in the literature to describe the association of a uterine STUMP with extensive retroperitoneal lymphocystic malformations. Uterine STUMP is a subgroup of uterine fibroids that requires more studies to enlighten its specific pathologic and clinical characteristics. ER -