Supplementary Material for: A rare case of a plasmacytoid and sarcomatoid differentiated urothelial bladder carcinoma with a single metastasis to the right ventricle of the heart and rapid review of single heart metastasis in bladder cancer

Background: Distant metastases and especially single side metastases of non-muscle invasive bladder cancer (NMIBC) without regional progression in lymph nodes are extremely uncommon and rare. Summary: We report a case of a plasmacytoid and sarcomatoid differentiated urothelial NMIIC with a single metastasis to the right ventricle of the heart, which was surgically resected, but the patient died shortly after the resection with progressive metastatic disease. To the best of our knowledge, this is the first case with two different variant histologies in NMIBC with a single heart metastasis. Furthermore, we conducted a rapid review using MEDLINE regarding single heart metastasis of bladder cancer. Four cases have been identified. Interestingly, with two cases of variant histology and one with single plasmocytoid differentiation, also being NMIBC. Key messages: These findings underline the aggressiveness of the variant histologies in NMIBC, especially plasmocytoid differentiation, and may favor an early and aggressive treatment regimen. Further scientific research concerning the optimal treatment of histologically variant bladder cancer is absolutely needed.