Multiple primary lung cancer versus intrapulmonary metastatic cancer: A case of multiple pulmonary nodules

Abstract

A preoperative chest computed tomography examination of the right breast in a 52-year-old woman with breast cancer revealed multiple nodules in both lungs. The nodule in the apical segment of the upper lobe of the right lung was larger, at a diameter of approximately 2.1 cm. The patient underwent resection of the right breast, followed by thoracoscopic wedge resection of four pulmonary nodules. Hematoxylin and eosin staining and immunohistochemistry showed that the nodules in the apical and anterior segments of the upper lobe and the paravertebral nodule in the lower lobe of the right lung were primary adenocarcinoma, and the subpleural nodule in the lower lobe of the right lung was infiltrated with inflammatory cells. Exon sequencing was conducted in the resected tissue samples and blood specimens. According to the characteristics of the somatic mutations, the nodule in the apical segment of the upper lobe of the right lung was primary lung adenocarcinoma, the nodule in the anterior segment of the upper lobe and the paravertebral nodule in the lower lobe of the right lung were intrapulmonary metastatic cancer, and the subpleural nodule in the lower lobe of the right lung indicated early stage tumor progression. This case provides new evidence that conducting gene detection in multiple tissue samples from patients who have undergone resection may assist to determine the relationship among multiple nodules in the lung to exclude lung metastasis of breast cancer.

Keywords: Gene mutation; intrapulmonary metastatic cancer; molecular detection; multiple primary lung cancer.

Figure 1

Three‐dimensional computed tomography image reconstruction of (a1–3) the 2.1 cm diameter nodule in the apical segment and the (b1–3) the 0.4 cm diameter nodule in the anterior segment of the upper lobe of the right lung; (c1–3) the 0.4 cm diameter subpleural nodule, and (d1–3) the 0.6 cm diameter paravertebral nodule in the lower lobe of the right lung.

Figure 2

Hematoxylin and eosin (HE) staining of the nodule (a) in the apical segment and (b) the anterior segment of the upper lobe of the right lung. Adenocarcinoma infiltration was observed in the lung tissue, and acinar was the dominant type. (c) HE staining of the subpleural nodule slice in the lower lobe of the right lung. Inflammatory cell infiltration was observed in the lung tissue. (d) HE staining of the paravertebral nodule slice in the lower lobe of the right lung. Adenocarcinoma infiltration was observed in the lung tissue, and acinar was the dominant type. (e) HE staining of the lump slice in the right breast, with the breast infiltrating ductal carcinoma. The lesion was ductal carcinoma in situ. (f) HE staining of the lymph node slice in the right armpit.