Published online Jul 24, 2019. doi: 10.5306/wjco.v10.i7.269
Peer-review started: January 4, 2019
First decision: March 15, 2019
Revised: May 25, 2019
Accepted: July 16, 2019
Article in press: July 16, 2019
Published online: July 24, 2019
Breast metastasis from extra mammary malignancies is rare. An incidence of 0.2%-1.3% has been reported in the literature, including that from different types of malignant neoplasms.
We present a case of a 29-year-old nonsmoking woman with breast metastasis from lung adenocarcinoma. Computed tomography revealed atelectasis in the right middle lobe of the lung and ipsilateral pleural effusion. Additionally, on physical examination, a small mass was noted in her right breast. The patient underwent bronchoscopy, needle thoracentesis, and breast biopsy. Following cytology, histology and immunohistochemistry, primary lung adenocarcinoma with metastasis to the breast was diagnosed. Only 63 cases, including our patient, have been reported in the literature since 2000, and this is the second in a woman under 30 years of age.
This atypical presentation may cause a significant diagnostic dilemma, but the contribution of immunohistochemistry is crucial to the accuracy of the final diagnosis.
Core tip: We present the second case of lung adenocarcinoma with metastasis to the breast in a patient under 30 years of age. This is a rare entity in oncology and even more so in this age group. There have only been 63 reported cases of breast metastasis from lung adenocarcinoma over the last eighteen years. A clear correlation between the side of primary lung cancer and the side of breast metastasis can be identified. Due to the infrequency of this phenomenon, the diagnosis may cause a significant dilemma. Nevertheless, immunohistochemistry plays a key role in the final diagnosis.