What hormonal secretion from small cell lung carcinoma could cause muscle weakness and hypertension?

• A. ADH (vasopressin)
• B. Adrenocorticotropic hormone
• C. Calcitonin
• D. Parathyroid hormone

Answer: (B)

Small cell lung carcinoma, also known as small cell lung cancer (SCLC), is known for its ability to produce various paraneoplastic syndromes due to the secretion of certain hormones. One of the key hormones that this cancer can secrete is adrenocorticotropic hormone (ACTH).

ACTH stimulates the adrenal glands to produce cortisol, which can lead to Cushing's syndrome. Symptoms of Cushing’s syndrome include hypertension (high blood pressure), muscle weakness, and other manifestations such as weight gain, changes in fat distribution, and skin changes. The muscle weakness results from protein catabolism and the effect of excess cortisol on muscle tissue, while hypertension arises due to cortisol's effects on fluid retention and vascular tone.

The other hormones mentioned do not typically relate to the muscle weakness and hypertension caused by small cell lung carcinoma. For example, while ADH (vasopressin) can lead to fluid retention and hyponatremia (dilution of sodium in the blood), it does not directly cause muscle weakness or hypertension in the same manner as ACTH does. Additionally, calcitonin and parathyroid hormone are primarily involved in calcium homeostasis and would not account for the symptoms of muscle weakness and hypertension related to SCLC.