Not everything is as it seems: a rare form of metastatic breast cancer

Abstract

Breast cancer is the most prevalent cancer and the leading cause of cancer-related death among females worldwide. Despite all therapeutic advances, metastatic breast cancer is still associated with a median overall survival of 3 years. Alongside this condition, bladder metastases of solid neoplasms are rarely observed. In this setting, the secondary bladder tumors with an origin in breast cancer occur in 2.5% of cases in some series. The authors report the case of a 68-year-old female with stage IV breast cancer (bone metastasis) treated with anastrozole, who presented with peripheral edema and renal failure with a creatinine clearance of 12.5 mL/min. After hospital admission, the patient was diagnosed with new liver lesions and bladder involvement with bilateral hydronephrosis. She was submitted to bilateral percutaneous nephrostomies with improvement in renal function. There was a high suspicion of primary bladder tumor in this patient who was a previous smoker, with a family history of high-grade bladder carcinoma (her mother). Liver and transurethral biopsies were performed, and histological examination was consistent with breast cancer metastases. The patient started treatment with capecitabine and denosumab, remaining clinically stable after 3 months of treatment. This case report underlines the diagnostic challenges of bladder metastases in a patient with multiple risk factors for bladder cancer and without evident clinical symptoms. Even though this is a rare entity, the close surveillance of metastatic breast cancer is important in order to allow early detection of new metastatic sites and their treatment to preserve the quality of life in these patients.

Keywords: Breast Neoplasms; Hydronephrosis; Urinary Bladder Neoplasms.

Figure 1. Computed tomography scan. A – Infiltrative lesion of the bladder floor, making it difficult to establish a cleavage plane with the vaginal dome, and infiltrating both orifices of the ureters. B – Bilateral hydronephrosis.

Figure 2. Photomicrographs of the biopsy specimen. A – Preserved urothelial mucosa (on the right) and mucosa involved by the neoplasm (on the left), with extensive involvement of the chorion by sheets or small nests of bulky neoplastic cells (H&E, 10X). B – Intense and diffuse expression of cytokeratin 7 by the neoplastic cell population on the left (10X). C – Intense and diffuse expression of GATA3 by the neoplastic cell population on the left (10X). D – Intense and diffuse expression of the estrogen receptors by the neoplastic cell population, and the absence of the ER expression by the residual surface urothelium (10X).

Figure 3. Immunohistochemical photomicrographs of negative staining for uroplakin III in a collection of neoplastic cells. A – Liver biopsy. B – Bladder biopsy.