Synchronous Metastasis of Renal Cell Carcinoma Presenting as a Primary Breast Tumor: A Rare Case Report

Abstract

In the context of cancer prevalence in India, breast cancer is the most common leading site for women, followed by cervical cancer.1 Globally, kidney cancer accounts for approximately 2% of all neoplasms and cases of extramammary malignancies metastasizing to the breast are extremely rare occurring in only 0.5-2% of cases2. Metastatic renal cell carcinoma to the breast presenting as a breast primary is a rare entity and very few sporadic cases are mentioned in the literature3. The article discusses a specific case involving a 70-year-old woman who presented with a right breast lump of short duration that was initially diagnosed as invasive breast carcinoma through a core needle biopsy. However, further radiological investigations revealed a large exophytic mass in the right kidney. After a multidisciplinary discussion, the case was determined to be a dual primary cancer, leading to a surgical treatment plan that included a lumpectomy with sentinel node biopsy and nephrectomy. The histopathological examination ultimately confirmed that the breast lump was a metastatic renal cell carcinoma, highlighting the rarity of such occurrences.