Contralateral breast metastasis from pulmonary adenocarcinoma: two cases report and literature review

Abstract

Carcinoma metastatic to breast from extra-mammary malignancy is rare and only accounts for 0.4-1.3% of all breast cancer. Two rare cases of single breast metastasis from pulmonary adenocarcinoma were reported here with a brief review of the pertinent literature. The only complaint of the these two female patients was painless breast mass found recently. Most breast metastasis previously reported are present in the upper outer quadrant, however, in our study, one case was found to be located in the lower inner quadrant and the other in the upper inner quadrant. Tumor cells from breast biopsy were immune-positive for thyroid transcription factor-1. The two patients survived 5 and 8 months, respectively, following the diagnosis of both the primary lung tumor and the breast metastasis. Breast metastasis from lung adenocarcinoma is rare but does exist. The awareness of this possibility may help to differentiate the tumor from primary breast carcinoma. Clinical history and immunohistochemical studies are essential to reach the final diagnosis.

Keywords: Lung neoplasms; breast neoplasm; neoplasm metastasis.

Figure 1

Preoperative radiology of lesion in patient case 1.A. Chest CT image of the apicoposterior segment showed a round, 3.2 cm × 3.1 cm mass in the right lung; B. CT scan also demonstrated a 3 cm-diameter subcutaneous mass in the left breast; C. MRI revealed a metastasis to the 3^rd lumbar vertebrae. Arrows indicate the tumor lesion.

Figure 2

Preoperative radiology of mass in patient case 2. A. Chest CT image disclosed a soft tissue mass (3.7 cm × 4.2 cm × 4.4 cm) in the inferior lobe of the left lung; B. A 1cm-diamete soft tissue round mass was present in the right breast; C. MRI revealed a metastasis to the right femur. Arrows indicate the tumor lesion.

Figure 3

Histological appearance of the primary lung tumor and breast metastasis in case 1.A. The lung puncture biopsy tissue H & E staining showed poorly differentiated adenocarcinoma; B. The breast biopsy tissue H & E staining showed irregular and solid malignant glands infiltrating the dense fibrohylinized breast stroma with focal necrosis (Arrow); C. The tumor cells were TTF-1 positive. Original images were taken with the magnification of 100×.

Figure 4

Histological appearance of the primary lung tumor and breast metastasis in case 2. A. The lung puncture biopsy tissue H & E staining showed poorly differentiated adenocarcinoma; B. The breast biopsy tissue H & E staining showed cribriform glands infiltrating the dense fibrohylinized stroma; C. Tumor cells were immuno-positive to TTF-1. Original images were taken with the magnification of 100×.