Abstract and Introduction
Abstract
Introduction Adrenocorticotropic hormone-independent macronodular adrenal hyperplasia, characterized by bilateral macronodular adrenal hypertrophy and autonomous cortisol production, is a rare cause of Cushing's syndrome. Bilateral adrenalectomy is considered the standard treatment for adrenocorticotropic hormone-independent macronodular adrenal hyperplasia but obliges the patient to receive lifetime steroid replacement therapy subsequently, and may increase the patient's risk of adrenal insufficiency. These circumstances require surgeons to carefully consider operative strategies on an individual basis.
Case presentation We performed successful laparoscopic adrenalectomy on four patients with adrenocorticotropic hormone-independent macronodular adrenal hyperplasia. Computed tomography scans showed bilateral adrenal enlargement in all patients. Case 1: a 56-year-old Japanese woman presented with obvious Cushing's symptoms during treatment for diabetes mellitus and hypertension. Case 2: a 37-year-old Japanese man also presented with Cushing's symptoms during treatment for diabetes mellitus and hypertension. These patients were diagnosed as Cushing's syndrome caused by adrenocorticotropic hormone-independent macronodular adrenal hyperplasia based on endocrinologic testing, and underwent bilateral laparoscopic adrenalectomy. Case 3: an 80-year-old Japanese woman was hospitalized due to unusual weight gain and heightened general fatigue, and was diagnosed as Cushing's syndrome caused by adrenocorticotropic hormone-independent macronodular adrenal hyperplasia. She underwent unilateral laparoscopic adrenalectomy due to high operative risk. Case 4: a 66-year-old Japanese man was discovered to have bilateral adrenal tumors on medical examination. He did not have Cushing's symptoms and was diagnosed as subclinical Cushing's syndrome due to suppressed adrenocorticotropic hormone serum levels and loss of cortisol circadian rhythm without abnormal levels of serum cortisol. He underwent unilateral laparoscopic adrenalectomy. During follow-up, serum cortisol levels were within the normal range in all cases, and serum adrenocorticotropic hormone levels were not suppressed. Further, cases with Cushing's syndrome experienced clinical improvement.
Conclusions We were able to effectively treat adrenocorticotropic hormone-independent macronodular adrenal hyperplasia in patients with obvious Cushing's symptoms by laparoscopic bilateral adrenalectomy, which promptly improved symptoms. Further, unilateral adrenalectomy was effective for treating an older patient at high operative risk and a patient with subclinical Cushing's syndrome.
Introduction
Adrenocorticotropic hormone (ACTH)-independent macronodular adrenal hyperplasia (AIMAH), an impairment demonstrated by bilateral macronodular adrenal hypertrophy and autonomous cortisol production, is a rare cause of Cushing's syndrome. Although bilateral adrenalectomy is considered the standard treatment for AIMAH, patients receiving this treatment are subsequently obliged to receive lifetime steroid replacement therapy and may be susceptible to adrenal insufficiency. Given these concerns, the operative strategy for treating AIMAH must be considered carefully for each individual case.
Here we report the surgical and clinical aspects of four cases of AIMAH that were treated by laparoscopic adrenalectomy, including two requiring bilateral adrenalectomy.