Intravenous Leiomyomatosis—A Single Centre Experience and Literature Review

Background/Objectives: Intravenous leiomyomatosis (IVL) is a rare, histologically benign proliferation of uterine smooth-muscle cells that extend intravascularly. The clinical significance of IVL lies in the potential for mechanical obstruction of the major veins and heart, as well as possible thromboembolic complications. Methods: A retrospective case series included four patients with confirmed IVL, treated at the Clinic for Gynaecology and Obstetrics “Narodni front” between 1 January 2020 and 31 December 2025. The following were recorded: medical history, imaging diagnostics (ultrasound, MRI), operative findings, histopathology, and follow-up data. The study was approved by the Ethics Committee, and written informed consent for participation in the study was obtained from all the patients. Results: The series included four patients aged 40 to 73 with histologically confirmed IVL who were treated surgically. In one patient, an intraoperative complication occurred in the form of sigmoid colon lesion and consequential resection, requiring surgical reconstruction, while the remaining procedures were completed without major complications. Histopathological findings in all cases indicated benign smooth-muscle differentiation with the presence of intravascular nodules of smooth-muscle cells (IVL). Residual disease and recurrence were documented in one patient. Conclusions: Our cases reflect a diverse spectrum of clinical presentations of IVL indicating the heterogeneity of the disease and the importance of a multimodal, multidisciplinary approach to the optimal management of this rare entity. The absence of further disease progression in our patients following bilateral oophorectomy, i.e., iatrogenic menopause, suggests the possible hormonal dependence of IVL.