Endometrial Cancer Diagnosed by the Presence of Bone Metastasis and Treated with Zoledronic Acid: A Case Report and Review of the Literature

Bone metastasis from endometrial cancer is rare. We report a case of endometrial cancer which was diagnosed by the presence of bone metastasis and treated with zoledronic acid. A 57-year-old woman complaining of progressive right hip pain consulted an orthopedist. She had no gynecologic complaints. X-rays revealed an osteolytic lesion of the right ischium. Bone scintigraphy was subsequently carried out and showed isotope accumulation in the right ischium. Computed tomography revealed an enlarged uterus; the patient consequently consulted a gynecologist. Histological sections of an endometrial biopsy showed endometrioid adenocarcinoma. Hysterectomy and bilateral salpingo-oophorectomy, as well as bone biopsy of the right ischium, were therefore carried out. A moderately differentiated endometrioid adenocarcinoma was expressed in the corpus. Histopathological examination of the bone biopsy also revealed adenocarcinoma. The final diagnosis was stage IVB endometrial cancer with bone and lung metastasis. Good pain relief was achieved due to chemotherapy. However, 2 months after completion of the chemotherapy, the patient was administered zoledronic acid because her hip pain had gradually increased. Following zoledronic acid administration, the hip pain reduced. Radiotherapy was then given for the right ischial metastasis after the ninth course of zoledronic acid therapy because the metastasis site had increased and the possibility of a pathological fracture had risen. However, the patient died 21 months after the initial treatment because of disease progression.