RESUMEN
BACKGROUND: We present an unusual case of a left axillary lymph node metastasis from a primary dedifferentiated endometrial carcinoma. This pattern of metastasis is likely the result of circulating tumor cells reaching the node through its arterial blood supply. CASE PRESENTATION: In this report, a 68-year-old white woman with a dedifferentiated endometrial carcinoma underwent a hysterectomy. She later developed an enlarged axillary lymph node due to metastatic dedifferentiated endometrial carcinoma, treated with chemotherapy and anti-programmed cell death protein 1 immunotherapy resulting in a complete clinical and radiological response. CONCLUSION: A review of the literature reveals the rarity of blood-borne lymph node metastasis, especially with uterine carcinoma. Immunotherapy has shown promising results in the treatment of some subtypes of metastatic uterine carcinoma.