Pathology: USMLE Q No. 8

[Cardiac Arrest]

A 48-year-old man complains of extreme fatigue, weakness, and lightheadedness when he stands up quickly from a seated position. The patient is normotensive when lying down; when sitting, his blood pressure drops and his pulse rate increases. There is diffuse brown pigmentation of the buccal mucosa. ACTH is elevated and serum cortisol levels are low. What is the primary pathology?

A. Adenoma of the pituitary gland
B. Adrenal cortical adenoma
C. Autoimmune destruction of adrenals
D. Diffuse hyperplasia of adrenals
E. Necrosis of the pituitary gland

[GoldenButterfly]

C autoimmune destruction of adrenals

[Cardiac Arrest]

Option C (Autoimmune destruction of adrenals) is correct. The clinical features are of Addison’s disease. The low cortisol and raised ACTH suggest nonfunctioning adrenal cortex. ACTH has melanocyte-stimulating properties that lead to pigmentation. The most common cause for Addison’s is autoimmune destruction of adrenals.

Option A (Adenoma of the pituitary gland) is incorrect. If related to adrenal function, it produces excess ACTH and low corticol levels in the serum. The clinical features will be of Cushing’s syndrome.

Option B (Adrenal cortical adenoma) is incorrect. This may be clinically silent if it is nonfunctioning or may produce Cushing’s syndrome or Conn’s syndrome due to excess production of glucocorticoids or mineralocorticoids.

Option D (Diffuse hyperplasia of adrenals) is incorrect. This leads to excess activity of the adrenals, leading to Cushing’s syndrome. Cortisol levels will be raised and ACTH will be low.

Option E (Necrosis of the pituitary gland) is incorrect. The clinical picture is Sheehan’s syndrome and is usually seen in postpartum state or sickle cell crisis. If it results in loss of ACTH, then the cortisol levels also will be low.

[uday]

I also feel its c

[f_ameer376]

thhhhhhhanx