Endocrine Abstracts

Paragangliomas and Pheochromocytomas are tumors originated from chromaffin cells (Pheochromocytomas (PHEO): adrenal glands; Paragangliomas (PGL):paravertebral thoracic, abdominal, and/or pelvic sympathetic ganglia, and glossopharyngeal and vagal neck and skull base parasympathetic ganglia). Catecholamine hypersecretion predominates in PHEO, while PGL are oligosymptomatic with compression-related symptoms. The authors report the case of a 33-year-old male with an incidental retroperitoneal PGL, detected during an investigation for urinary lithiasis (abdominal pain that shifted to different location, varying in intensity), without clinical evidence of catecholamine hypersecretion. The abdominal ultrasound identified a well-defined 5.0×4.5 cm hypoechoic nodular area at the right retroperitoneal region, above the renal pelvis, dislocating the renal vein anteriorly. The image was confirmed by CT (a 5.6×4.5×4.1 cm nodular area anterior to the right adrenal gland without a cleavage line with the inferior cava vein), MRA (a 5.4×3.5×4.6 cm nodular area anterior to the right adrenal gland), and PET/TC with FDG (a right retroperitoneal 5.2×3.8 cm mass that dislocated the inferior cava vein at the confluence of the renal veins; SUVmax =29.7). ¹²³I-MIBG scintigraphy showed a discrete tumoral uptake. Ultrasound-guided biopsy: the patient presented a hypertensive peak during this procedure and was successfully medicated. He did not present arterial hypertension during the follow-up. Histopathology: suggestive of paraganglioma and neuroendocrine tumor.chemical investigation for catecholamines and plasmatic metanephrines hypersecretion: negative. Surgery: anterior laparotomy (without pharmacological preparation, since the tumor was non-secreting) without complications. Histopathology: paraganglioma/neuroendocrine tumor. Post-op follow-up: normal levels of metanephrines/catecholamines. I¹²³ MIBG scintigraphy without evidence of the previously described lesion in the right lumbar region. No recurrence or clinical evidence of disease after a 5-year period.

Conclusion: Despite the tumour dimensions, there were no symptomatology previously to the diagnosis and no recurrence at a 5-year follow-up.