ACTH-secreting pheochromocytoma case highlights diagnostic complexity and successful surgical management

Corticotropin (ACTH)-secreting pheochromocytomas are exceptionally rare neuroendocrine tumors. They present a unique diagnostic and therapeutic challenge due to the simultaneous excess of both catecholamines and cortisol, leading to a complex clinical picture that can mimic both typical pheochromocytoma and Cushing's syndrome. Standard diagnostic imaging like MIBG scintigraphy can be negative, further complicating identification. Current standard-of-care for pheochromocytoma involves surgical resection, but the dual hormonal excess in ACTH-secreting variants necessitates specialized preoperative stabilization to manage both hypertensive crises and adrenal insufficiency risks.

Researchers present a case of a 38-year-old man experiencing hypertension and episodic adrenergic symptoms. Diagnostic workup included biochemical analysis revealing elevated metanephrines and ACTH-dependent hypercortisolism. Imaging identified a right adrenal mass suggestive of pheochromocytoma, but metaiodobenzylguanidine (MIBG) scintigraphy yielded negative results. The patient underwent preoperative preparation with alpha- and beta-blockade to control catecholamine effects, alongside intraoperative steroid coverage to manage potential adrenal insufficiency. Subsequently, a laparoscopic adrenalectomy was performed to remove the tumor.

Biochemical tests confirmed elevated metanephrines and ACTH-dependent hypercortisolism, indicating a dual hormonal excess. Imaging localized a right adrenal mass consistent with pheochromocytoma, though the MIBG scan, typically used for pheochromocytoma localization, was unexpectedly negative. Histopathological examination of the resected adrenal mass confirmed it as a pheochromocytoma, notably with focal ACTH expression. The tumor also exhibited malignant potential, scoring PASS 5 on the Pheochromocytoma of the Adrenal Gland Scaled Score. Postoperatively, the patient required transient glucocorticoid replacement therapy. Most significantly, he achieved complete normotension without the need for any antihypertensive medications. This outcome highlights the successful resolution of both catecholamine and cortisol excess following surgical intervention.

The patient achieved normotension postoperatively without antihypertensives, demonstrating successful resolution of dual hormonal excess.