Perivascular epithelioid cell tumour (PEComa) of the urinary bladder: report of a case

Abstract

<h3>Case summary</h3> An 82-year-old female underwent biopsy and subsequent right partial cystectomy of a bladder mass showing extension into the pelvis. Macroscopically the resection specimen showed ulcerated urothelium overlying a relatively circumscribed heterogenous and haemorrhagic mass within the bladder wall. Histology of both the biopsy and the resection specimen were concordant, demonstrating the morphological and immunohisto-chemical profile of a PEComa. <h3>Discussion</h3> The PEComa family of neoplasms may arise anywhere within the body, and typically display spindled, epithelioid or an admixture of these patterns microscopically. PEComa of the urinary bladder israre, with only nine cases having been previously reported. Accordingly the more common benign and malignant differential diagnoses should first be excluded, as they show different biological behaviour. Criteria describing pathological features that may predict malignant behaviour in these neoplasms have been proposed. However their significance in PEComas of the urinary bladder is unknown and the little available evidence suggests they behave indolently in this location. Consequently precise recommendations regarding follow-up have not yet been established. <h3>Conclusion</h3> In order to better understand the pathogenesis, biological behaviour and prognosis of PEComas, further evaluation of the PEComa family of neoplasms needs to be undertaken, including long-term follow-up.