Introduction: Pheochromocytomas are catecholamine-secreting tumors arising from the chromaffin cells of the adrenal medulla. We describe an unusual case of pheochromocytoma located in the infrarenal area and associated with bilateral adrenal hyperplasia.
Case presentation: A 70-year-old patient was admitted for syncope, diaphoresis, and high blood pressure. Computed tomography showed a 73x70x72 mm retroperitoneal mass of the left infrarenal area. High levels of metanephrine and noradrenaline were found in the urine. A tumor resection was performed. A few days after surgery, the blood pressure suddenly decreased and could not be restored, resulting in the death of the patient. Histopathological examination of the surgical specimen revealed a proliferation of monotonous cells, with eosinophilic cytoplasm, round nuclei with prominent nucleoli arranged in clusters, and capsular and vascular invasion. The tumor cells expressed synaptophysin and chromogranin, without positivity for inhibin A or S100 protein. At the autopsy, both adrenal glands showed hyperplasia but unrelated to the tumor mass. The histological aspect, location, and immunophenotype indicated an ectopic infrarenal pheochromocytoma.
Conclusions: In patients with pheochromocytoma developed on ectopic adrenal tissue, clinical management might be difficult, and diagnosis can be sometimes established only based on post-mortem histopathological examination. Autopsy can be extremely useful in such cases with unexplained evolution.