Diagnostic and Therapeutic Challenges in Concurrent Addison's Disease and Acromegaly.

The simultaneous occurrence of Addison's disease and acromegaly presents a unique and complex clinical challenge. Addison's disease, characterized by autoimmune adrenal destruction, results in cortisol and aldosterone deficiencies, while acromegaly stems from excessive growth hormone secretion, usually due to a pituitary adenoma. Their coexistence complicates diagnosis and management due to overlapping systemic effects. We report a 53-year-old woman initially diagnosed with Addison's disease, presenting with fatigue, hypotension, and hyperpigmentation. Four years later, she developed acromegalic symptoms, including acral enlargement and hyperhidrosis. Laboratory assessments confirmed elevated insulin-like growth factor-1 (IGF-1) and growth hormone levels, with imaging revealing two pituitary microadenomas. The patient underwent transsphenoidal surgery, achieving tumor debulking and hormonal stabilization. Addison's disease management involved hydrocortisone, fludrocortisone, and levothyroxine, complicated by metabolic instability and hypertension. Additional comorbidities included diabetes, glaucoma, and sleep apnea, necessitating a multidisciplinary approach. Long-term follow-up demonstrated stable IGF-1 levels and no recurrence. This case illustrates the rare co-occurrence of Addison's disease and acromegaly, highlighting diagnostic delays, difficulties in endocrine management, and the critical importance of structured long-term follow-up. Special attention is paid to the impact of incomplete mineralocorticoid evaluation, missed opportunities for early diabetes screening, and evolving pituitary insufficiency after tumor resection.