Endometrial Metastasis of Lung Adenocarcinoma: A Report of Two Cases

BACKGROUND The female genital tract is an uncommon site of involvement for extragenital malignancies. Ovarian, vaginal, and cervical metastasis has been described in the literature. Uterine corpus and, particularly, endometrial involvement are exceedingly rare. As the incidence of lung cancer is rising in the female population, metastatic uterine involvement by lung cancer is also being reported in the medical literature. Here, we report two cases of endometrial metastasis from primary lung adenocarcinoma. CASE REPORT The first case is a 55-year-old woman diagnosed with stage III lung adenocarcinoma who received initial treatment with sequential chemotherapy and radiotherapy, which resulted in complete response to treatment. However, patient was found to have recurrence soon after completion of initial treatment. Biopsy of a hypermetabolic lesion confirmed endometrial metastasis. The second case is a 51-year-old woman who presented with stage IV lung adenocarcinoma with metastasis to the uterus. EGFR mutation analysis of the lung mass and endometrial biopsy revealed epidermal growth factor receptor L858R mutation in exon 21. She had a positive response to EGFR-directed treatment of all areas of disease, including the uterus. CONCLUSIONS Uterine metastasis from lung adenocarcinoma is uncommon and difficult to differentiate from primary uterine cancer. The possibility of lung cancer metastasis should be considered in patients who have adenocarcinoma on biopsy of uterine lesions.