Asymptomatic Bladder Metastasis from Breast Cancer

Introduction. Breast cancer is the most common nondermatologic cancer in women. Common metastatic sites include lymph nodes, lung, liver, and bone. Metastases to the bladder are extremely rare, with all reported cases presenting with urinary symptoms. Case Report. Herein, we report the first case of completely asymptomatic bladder metastasis from breast cancer, occasionally revealed, 98 months after the initial diagnosis of lobular breast carcinoma, by a follow-up computed tomography scanning showing thickening of left bladder wall and grade II left hydronephrosis. A positive staining for estrogen and progesterone receptors was confirmed by immunohistochemistry. Discussion. The reported case confirms that bladder metastases from breast cancer tend to occur late after the diagnosis of the primary tumor and, for the first time, points out they can be asymptomatic. Conclusion. Such data support the need for careful follow-up and early intervention whenever such clinical situation is suspected. 1. Introduction Breast cancer (BC) is the most common malignant disease affecting women, with the exception of nonmelanoma skin cancers, and the second leading cause of death for cancer in women, mainly due to metastatic spread [1, 2]. BC usually metastasizes to lung, bone, liver, lymph nodes, and skin but rarely spreads to other sites, such as urinary bladder and retroperitoneum [3]. As a matter of fact, there are less than 40 cases in the literature of bladder metastases from BC, with quite heterogeneous presentation and histological features. Herein, we report the first case of completely asymptomatic bladder metastasis from BC, occasionally revealed by a follow-up abdominal computed tomography (CT) scanning. Diagnostic and therapeutic challenges of such uncommon clinical condition are discussed. 2. Case Report A 45-year-old female patient underwent right quadrantectomy with ipsilateral axillary node dissection followed by radical mastectomy in January 2005. Pathology revealed a pT2N3M0 lobular carcinoma, with positive estrogen receptor (ER, 70%) and progesterone receptor (PR, 80%) immunostainings, proliferative index (Ki67/MIB-1) as high as 15%, and negative HER2/neu status. The patient underwent 4 cycles of adjuvant chemotherapy with doxorubicin and cyclophosphamide, as well as locoregional radiotherapy. She also received hormonal treatment with LHRH analogues and tamoxifen until June 2007, when she was switched to exemestane. In January 2010, vertebral lumbar metastases were diagnosed and treated with radiotherapy, letrozole, and bisphosphonates. In October