Recurrent primary haemangiopericytoma of the bladder: A case report and literature review.

Haemangiopericytoma (HPC) is a rare soft-tissue tumour with great histological variability and unpredictable clinical and biological behaviour. HPC of the bladder is exceedingly rare and carries uncertain malignant potential. The current study reports a case of HPC of the bladder in a 48-year-old female, who was admitted to the Sir Run Run Shaw Hospital (Hangzhou, China) due to a large bladder mass. The patient exhibited no mass-related symptoms, such as pain, gross haematuria or urinary irritation. Seven years prior to admission, the patient underwent surgical resection of a bladder mass, which was determined to be HPC. Computed tomography scans showed a well-defined, heterogeneously enhancing solid cystic mass in the bladder. The patient underwent complete excision of the tumour and a partial cystectomy. The histopathological diagnosis was HPC of the bladder. The post-operative recovery was uneventful and no evidence of recurrence or metastasis was identified during two years of follow-up. The clinical and histological features, and the treatment and prognosis of this tumour are discussed together in the present study, with a review of the literature.