From tumour to tumour: Metastasis of invasive ductal breast carcinoma to chromophobe renal cell carcinoma

The coexistence of two or more tumours in the same patient is unusual, but even rarer is the metastasis of one tumour to another. Most reports are based on evidence from autopsies; very few refer to surgical specimens. The most common primary tumour is pulmonary carcinoma and most frequent metastatic tumour is renal clear cell carcinoma. We present the case of a 54 year-old female with a past history of infiltrating ductal carcinoma of the breast with metastases in lung, lymph nodes and bone. Three months previously to her referral to us, she had developed a renal mass and underwent nephrectomy. Histopathology revealed a renal chromophobe cell carcinoma with intratumoral breast cancer metastasis. We describe the histopathological, immunohistochemical and molecular features and review the recent literature.