AIM: To investigate the clinicopathological characteristics, differential diagnoses, and prognostic implications of uterine metastasis originating from lung adenocarcinoma. METHODS: A retrospective clinicopathological analysis was performed on five cases of lung adenocarcinoma with uterine metastasis, supplemented by a literature review. RESULTS: Patients' ages ranged from 33 to 66 years (mean: 52.80±12.56 years). All patients were histologically confirmed to have lung adenocarcinoma. The metastatic sites included the uterine corpus (three cases), cervical leiomyoma (one case), and cervical endometrium (one case). Serum levels of carcinoembryonic antigen were elevated in three patients, and one patient exhibited a high-grade squamous intraepithelial lesion on the ThinPrep cytologic test. The predominant clinical presentations were abnormal vaginal bleeding (3/5 cases) or abdominal pain and bloating (1/5 cases), with one asymptomatic patient whose metastasis was incidentally discovered. Histologically, the tumors displayed glandular, nested, or solid growth patterns with focal degeneration, abundant eosinophilic or clear cytoplasm, and nuclear atypia. Immunohistochemically, the tumor cells were positive for thyroid transcription factor-1 (TTF-1), Napsin A, and cytokeratin 7 (CK7) in all cases, while negative for estrogen receptor (ER), progesterone receptor (PR), paired-box gene 8 (PAX-8), and p16. CONCLUSION: Lung cancer metastasizing to the uterus is exceedingly rare and is associated with non-specific clinical and morphological features. Immunohistochemical markers, particularly TTF-1, Napsin A, and CK7 positivity, combined with ER, PR, PAX-8, and p16 negativity, could help distinguish metastatic lung adenocarcinoma from primary uterine malignancies.
Haiyun et al. (Wed,) studied this question.