Abstract 92: Contemporaneous association of pheochromocytoma with Cushing's syndrome

Background: Pheochromocytomas are catecholamine secreting tumours of the adrenal gland. We report a rare case of adrenocorticotropic hormone-secreting pheochromocytoma. Case Report: A twenty-five-year-old male presented with excessive fatigue for one year. He had pain abdomen two weeks prior to the presentation. On examination, he was pale, emaciated, had tachycardia with normal blood pressure. Abdominal ultrasound revealed a right adrenal mass. There were no stigmata of Cushing's disease. His urinary metanephrine was 469.8 μg/24 hours, and nor-metanephrine was 3676.5 μg/24 hrs. Androstenedione, DHEA-S were normal. The 8 am cortisol was not suppressed with overnight 1mg dexamethasone. He had elevated ACTH (253.9 pg/mL). Calcium, phosphorous, prolactin levels were normal. He underwent laparoscopic resection of the tumour after adequate alpha and beta-blockade. The tumour measured 9x8.5x6 cm with no capsular or vascular invasion. Histopathology revealed tumour cells with round to irregular nuclei arranged in the Zellballen pattern. Tumour cells were diffusely positive for chromogranin A. Ki-67 index was 1-2%. Post-operatively 24-hour urinary metanephrine, normetanephrine and ACTH levels were normalized. Conclusion: This case report highlights the importance of complete biochemical evaluation in a patient with an adrenal mass even if biochemical evidence of pheochromocytoma is confirmatory.