A rare case of pediatric renal paraganglioma

Abstract

Objective To explore the clinical characteristics of renal paraganglioma(PGL). Methods The clinical data of a rare case of renal paraganglioma in a pediatric patient were reported and published cases of renal paragangliomas both domestically and internationally were reviewed. Results A 12-year-old male patient underwent surgery for a right renal mass, with histopathological confirmation revealing a renal paraganglioma. Immunohistochemical staining results were positive for CgA and S-100, while Ki-67 index showed positivity in hot spots at 20%. The SDHB stain was negative. Germline genetic testing detected a heterozygous mutation in exon 6 of the SDHB gene, c.641A＞C(p.Gln214Pro). Following surgery, local radiotherapy was administered to the operative area. A posto- perative 18F-FDG-PET/CT scan did not reveal any metastatic lesions. A total of 15 cases of renal paraganglioma have been reported at home and abroad since 2001, of which 8 were male and 7 were female, with an average age at diagnosis being (42±17) years old. Only 5 patients had hypertension preoperatively, and only 2 presented with typical clinical symptoms. Out of 8 patients who underwent catecholamine testing before surgery, only 4 demonstrated elevated levels. The maximum tumor diameter was (9.9±7.3) cm, with 67% (10 out of 15 cases) having tumors larger than or equal to 5 cm in diameter. In this group, 30% (3 out of 10 cases) had tumors that were S-100 negative, and 50% (2 out of 4 cases) had tumors with a Ki-67 index of ≥3%. Conclusions Renal paraganglioma is extremely rare, and some patients present without clinical symptoms and with normal catecholamine, making misdiagnosis more likely. Due to the frequent occurrence of large tumors and high Ki-67 indexes, such tumors carry a relatively higher risk of recurrence and metastasis. Therefore, close follow-up is essential after the operation.

Keywords

• kidney|paraganglioma|clinical features