Urinary bladder paraganglioma in childhood: a case report and review of the literature.

Bladder paraganglioma (BP) is a rare entity and is exceedingly uncommon in childhood. Pheochromocytomas/paragangliomas are components of several hereditary cancer syndromes, and up to 30% may be associated with germ-line mutations of genes, including VHL, RET, and SDH. We present a 16-year-old female who was admitted with macroscopic hematuria and anemia. A cystoscopy demonstrated a polypoid and hemorrhagic mass arising from the floor of the bladder. She underwent a transurethral resection of clinically suspected urothelial papilloma. A histologic examination of the tumor showed large polygonal cells with eosinophilic cytoplasm, arranged in a zellballen pattern, surrounded by a fibrous network. Immunohistochemical studies showed a strong expression of neuroendocrine markers and lack of reactivity for epithelial markers. The diagnosis of BP was established; eight months later, a recurrence was observed and the patient underwent a partial cystectomy. Our case represents the 1st BP in childhood reported in the literature with absent SDHB staining by immunohistochemistry. We discuss the clinical and pathologic findings and present a review of BP in childhood.