An uncommon manifestation of paraneoplastic cerebellar degeneration in a patient with high grade urothelial, carcinoma with squamous differentiation: A case report and literature review.

<bold>Background: </bold>Paraneoplastic neurological syndromes (PNS) are rare disorders associated with malignant tumours, which are triggered by autoimmune reactions. Paraneoplastic cerebellar degeneration (PCD) is the PNS type most commonly associated with ovarian and breast cancer. Two bladder cancers manifesting in PCD were previously reported. However, the cancers in these cases had poor outcomes.<bold>Case Presentation: </bold>Here, we present a 68-year old man with history of high-grade papillary urothelial carcinoma of the bladder. The patient suffered from persistent cerebellar ataxia accompanied by bladder cancer recurrence five months after transurethral resection of the bladder tumour (TURBt). Laboratory screening for the specific antibodies of paraneoplastic neurological syndromes revealed no positive results. Symptoms were not remitted after a 7-day-course of high-dose glucocorticoid therapy. To our surprise, the patient recovered fully after laparoscopic radical cystectomy. Postoperative pathology revealed that surgical specimens were urothelial carcinoma in situ (CIS) and squamous cell carcinoma of the bladder. The patient remained asymptomatic and there was no evidence of recurrence after the followup period of 11 months.<bold>Conclusion: </bold>To our knowledge, this is the third report of PCD in a patient with bladder cancer. This case showed that tumour resection cured the PCD. To assist clinical evaluation and management, literature regarding basic PNS characteristics and bladder cancers was reviewed. [ABSTRACT FROM AUTHOR]