A 47-year-old Korean woman with right middle lobe lung adenocarcinoma, malignant pleural effusion, and multiple lymph node and bone metastases, after three months of lung cancer diagnosis, presented with a palpable right breast mass. Images of the right breast demonstrated architectural distortion that strongly suggested primary breast cancer. Breast biopsy revealed metastatic lung cancer with a negative result for estrogen receptor (ER), progesterone receptor (PR) and mammaglobin, and a positive result for thyroid transcription factor-1 (TTF-1). We present a case of breast metastasis from a case of lung cancer with an extensive micropapillary component, which was initially misinterpreted as a primary breast cancer due to unusual image findings with architectural distortion.
Adenocarcinoma/drug therapy/*secondary ; Antineoplastic Combined Chemotherapy Protocols/therapeutic use ; Biopsy, Needle ; Bone Neoplasms/secondary ; Breast Neoplasms/drug therapy/*secondary ; Diagnosis, Differential ; Female ; Humans ; Lung Neoplasms/*pathology ; Lymphatic Metastasis ; Mammography ; Middle Aged ; Neoplasm Staging ; Tomography, X-Ray Computed ; Ultrasonography, Mammary