Retroperitoneal paraganglioma causing proximal ureteric obstruction in a child: diagnostic conundrum and immunohistochemistry characteristics (case report).

Paragangliomas are extremely rare neuroendocrine tumors with an incidence of 0.3 cases per million in children. They arise from several sites in the body including the orbit, ear, nose, larynx, carotid area, mediastinum, duodenum, and the genitourinary tract. Germline mutations have been identified in paragangliomas involving the proto-oncogene RET, tumor suppressor genes VHL, and NF1 The commonest clinical presentation is hypertension but incidentally detected forms have been reported during imaging and on a few occasions the diagnosis was missed. The authors report on a case of a 12-year-old male with a history of fever, left flank pain, vomiting, and headaches, finally diagnosed by pathological examination of a resected retroperitoneal mass invading the proximal left ureter. Immunohistochemistry was positive for neuron-specific enolase, NSE (chief cells), and S-100 protein (sustentacular cells) all consistent with paragangliomas. The challenges faced by the team in the preoperative evaluation and surgical treatment are reported.