MON-374 Composite Pheochromocytoma: Look and You Shall Find...

Background: Composite pheochromocytoma (CP) is a rare tumor which is composed of pheochromocytoma (or paraganglioma) and a non-pheochromocytoma component of similar embryonic origin, such as ganglioneuroma, ganglioneuroblastoma, neuroblastoma, malign schwanoma and neuroendocrine carcinomas. Abstract: We report two cases of adrenal CP with association of pheochromocytoma and ganglioneuromas followed in the Endocrine and Pathology Services of our institution. Case 1: A 39-year-old female, evaluated in August/2003 with clinical signs of adrenergic hypersecretion, a predominance of paroxysmal hypertension, and biochemical exams suggestive of pheochromocytoma with a preponderance of altered urinary levels of adrenaline and noradrenaline. The abdominal computed tomography showed a heterogenous nodular expansive lesion with 3.9 cm in the left adrenal and the right gland with normal aspect. She was submitted to a left video laparoscopic adrenalectomy preceded by alpha-blocker preparation. The histopathological diagnosis was pheochromocytoma associated with ganglioneuroma and the post-surgical follow-up has presented no intercurrences. Case 2: A 29-year-old female, evaluated in January/2018 for abdominal pain, fatigue, and diarrhea, without arterial hypertension. Abdominal ultrasound showed a heterogeneous nodular isoechoic lesion of 68 x 55 mm in the right adrenal. Magnetic resonance imaging confirmed the lesion of 72 x 65 x 69 mm with a hemorrhagic area of high protein level of 32 x 23 mm. Biochemistry was characterized by altered levels of free plasmatic adrenaline and noradrenaline. She was submitted to a right video laparoscopic adrenalectomy. The histopathological diagnosis was pheochromocytoma and areas of peripheric differentiation of ganglioneuroma. Conclusion: The association of pheochromocytoma with tumors of similar embryonic origin most frequently involves ganglioneuromas - present as the second component in 70% of the cases of CP. Our two cases, despite the pathological similarity, had different clinical presentation and progression. Nevertheless, considering the embryonic origin, the authors question the rare character of CP and wonder if this tumor is not underdiagnosed in clinical practice.