Breast Cancer Metastasis in a Renal Carcinoma Pulmonary Metastasis: A Rare Example of Tumor-to-Tumor Metastasis

Figure 3

Microscopic examination of the basal nodule biopsy specimen (H&E, 40x). Pulmonary parenchyma (upper left corner) with involvement of epithelial cells with the clear cytoplasm and well-defined cell membrane, interspersed within a highly vascularized stroma, compatible with ccRCC. Inside this, a distinct population cells, arranged in nests, with a more eosinophilic cytoplasm is identified, corresponding to the breast carcinoma.