Breast metastasis from primary lung adenocarcinoma in a young woman: A case report and literature review

Figure 1 Chest computed tomography scan. Atelectasis in the right middle lobe of the lung, ipsilateral pleural effusion, and enlarged lymph nodes in the mediastinum and right hilum.

Figure 2 Right breast ultrasound. Hypoechoic solid nodule (11.6 mm x 6.6 mm x 8.9 mm).

Figure 3 Breast biopsy showed adenocarcinoma infiltrating into the adjacent parenchyma. A: Ducts were not involved by the tumor, and no evidence of in situ carcinoma was obtained (x 40); B: Bronchoscopy biopsy (HE) showed poorly differentiated adenocarcinoma (x 40); C, D: Immunohistochemical staining for thyroid transcription factor-1 was positive on both breast (C) and lung specimens (D); E, F: GATA3 staining was negative in both breast (E) and lung tissue (F).

Figure 4 Distribution of immunohistochemical markers on the breast biopsies in the reviewed cases (including ours). ER: Estrogen receptor; PR: Progesterone receptor; HER2: Human epithelial growth factor receptor 2; TTF-1: Thyroid transcription factor 1; CK7: Cytokeratin 7; CK20: Cytokeratin 20; GCDFP15: Gross cystic disease fluid protein 15; GATA3: GATA-binding protein 3.