Endocrine Abstracts

JOINT3463

Introduction: Paragangliomas are rare neuroendocrine tumors arising from extra-adrenal chromaffin cells. While functional paragangliomas secrete catecholamines and present with symptoms such as hypertension, episodic headache and tachycardia, non-functional paragangliomas are asymptomatic and often discovered incidentally. Herein, we report a case of non-secreting retroperitoneal paraganglioma.

Case Report: A 62-year-old male presented to our department with acute-onset low back pain progressing for a few months. He additionally complained of headaches and muscle fatigue for several weeks. There was no history of neuropathy or trauma. The family history was positive for hypertension, diabetes mellitus and autoimmune disorders but there were no symptoms to suggest endocrine neoplasia syndrome. On admission, the physical examination was unremarkable with no palpable abdominal mass. His blood pressure was 120/70 mmHg, and his other vital signs were within normal range. Ambulatory blood pressure (BP) monitoring showed an average daytime BP of 123/74 mmHg and nighttime BP of 114/62 mmHg. Standard laboratory investigations were unremarkable. A lumbar spine Computed Tomography scan (CT) was performed and revealed a solitary well-defined mass located in the right renal hilum with a spontaneous density of 25 HU, measuring 40 × 27 × 37 mm. Then, an abdominal CT scan was performed, revealing a well-defined, multilobulated extra-renal retroperitoneal mass located in the right perihilar lower pole, exhibiting intense and early enhancement in the arterial phase with progressive enhancement in the portal and delayed phases. The mass was vascularized by a pedicle arising from the ipsilateral renal pedicle and measured 40 × 25 mm in axial dimensions with a height extension of 44 mm, which was more consistent with paraganglioma. There were no locoregional extension or evidence of secondary lesions. Laboratory findings showed also normal serum metanephrines and normetanephrines. (Normetanephrines: 89.9 pmol/l (139-808) and Metanephrines: 76.5 pmol/l (88-375) The patient underwent laparoscopic surgery without complications, and the histopathological study confirmed the diagnosis of paraganglioma.

Conclusion: The diagnosis of non-secreting paraganglioma is challenging, as there are no specific clinical or biological signs for early detection. Surgical excision remains the treatment of choice. Half of these tumors are malignant. The progression is characterized by the risk of late recurrences. Consequently, long-term follow-up is essential.