Breast cancer with synchronous massive metastasis in uterine myoma: A case report and literature review

Introduction: Metastasis of breast cancer to the uterus is an exceptionally rare occurrence, typically presenting with vaginal bleeding as the predominant symptom. Here, we present a case of synchronous lobular breast cancer metastasis to a uterine myoma. Main symptoms and/or clinical findings: A 42-year-old infertile patient was admitted to the gynecology clinic with the complaints of meno/metrorrhagia. Ultrasound revealed a 5 cm intramural myoma on the anterior wall of the uterus, leading to a myomectomy. The patient exhibited no symptoms related to breast cancer. Main diagnosis: Histomorphological and immunohistochemical findings were indicative of breast-derived lobular carcinoma metastasis into leiomyoma. Therapeutic interventions and outcomes: Positron emission tomography/computed tomography (PET/CT) scan revealed no pathological involvement beyond the breast and both axillary lymph nodes. The patient was diagnosed with stage IV breast lobular cancer and initiated chemotherapy treatment. Presently, the patient is undergoing regular monitoring at six-month intervals. Conclusion: Uterine metastasis from extragenital organ cancers is exceedingly rare. In this instance, lobular breast cancer metastasis was confined to the uterine myoma. Clinicians and pathologists should exercise caution regarding gynecological metastases in breast cancer cases. (c) 2024 Elsevier Espana, S.L.U. All rights reserved.