Abstract:

Objective To explore the clinical diagnosis and treatment of ectopic adrenocorticotropic hormone (ACTH) syndrome caused by recurrent adrenal pheochromocytoma, thus enhancing the awareness and attention of clinicians to such a rare disease. Methods Clinical data of a patient with ectopic ACTH syndrome caused by recurrent adrenal pheochromocytoma were retrospectively analyzed, and relevant literatures were reviewed. Results A 64-year-old female patient was admitted due to hyperglycemia for 8 years, accompanied by dizziness and weight loss for 2 months. She had a surgical history of right adrenal pheochromocytoma. The patient has now suffered from persistent hypokalemia. ACTH and cortisol (COR) levels were more than 10 times higher than the normal reference ranges. The high-dose and low-dose dexamethasone suppression test showed that the lease of ACTH was not suppressed. All six indicators in the blood catecholamine panel were significantly elevated. The combined plain and contrast-enhanced computed tomography (CT) scans of the chest and abdomen showed multiple occupying lesions in the right adrenal area and the right perirenal region, suggesting a possible recurrence of pheochromocytoma and multiple perirenal metastases. A conventional dose of phenoxybenzamine was administered for preoperative preparation, and laparoscopic resection of the right adrenal tumor was performed. The pathology suggested a pheochromocytoma of the right adrenal gland. The immunohistochemistry results showed CgA(+), NSE(+), Ki-67 (+ approximately 2%), Sny(+), and ACTH(-). After the surgery, ACTH and cortisol levels rapidly returned to the normal reference ranges. The follow-up examinations at 3, 6, and 12 months postoperatively indicated that catecholamines, ACTH, and cortisol were all within the normal reference ranges. The patient's blood pressure did not rise again, and the blood sugar decreased significantly compared to pre-treatment levels. The weight gradually returned to normal. Conclusion Ectopic ACTH syndrome caused by recurrent pheochromocytoma is a rare disease. Clinically, this possibility should be considered when encountering ectopic ACTH syndrome. Surgical resection is an effective treatment, and preoperative preparation should be completed in accordance with the standards for pheochromocytoma before surgery.

Key words: pheochromocytoma, adrenal gland, ectopic ACTH syndrome