A case with isolated ACTH deficiency accompanying chronic thyroiditis.

Area of Science:

• Endocrinology
• Internal Medicine

Background:

• Isolated adrenocorticotropic hormone (ACTH) deficiency is a rare condition affecting the pituitary gland's ability to stimulate the adrenal cortex.
• Coexistence of endocrine disorders can complicate diagnosis and management.

Observation:

• A 53-year-old male presented with fatigue, weight loss, weakness, hypotension, and hypoglycemia.
• Initial tests revealed elevated thyroid hormones (T3, T4) with undetectable thyroid-stimulating hormone (TSH), suggesting thyrotoxicosis, alongside subnormal growth hormone (GH) and exaggerated luteinizing hormone (LH) responses.
• Thyroid biopsy confirmed chronic thyroiditis with positive thyroid antibodies.

Findings:

• Replacement therapy with hydrocortisone normalized TSH response to thyrotropin-releasing hormone (TRH) and corrected T3/T4 levels, indicating resolution of the apparent thyrotoxicosis.
• GH and LH responses to provocative stimuli (arginine, L-Dopa, LHRH) normalized after hydrocortisone treatment.
• A review of 44 Japanese cases of isolated ACTH deficiency is included.

Implications:

• This case highlights the complex interplay between the pituitary and thyroid axes and the potential for misdiagnosis in coexisting endocrine conditions.
• Effective management of ACTH deficiency with glucocorticoids can restore normal pituitary function and resolve secondary endocrine abnormalities.
• Understanding these interactions is crucial for accurate diagnosis and comprehensive patient care in endocrinology.