p7 - guest1

[ArchivalUser]

A 67-year-old male smoker presents to his physician for a routine physical examination. Chest x-ray demonstrates
a 2-cm density on the left side. Laboratory studies are remarkable for a serum sodium of 134 mEq/L. The findings
may be attributable to tumor cell secretion of


A. adrenocorticotrophic hormone (ACTH)

B. antidiuretic hormone (ADH)

C. melanocyte-stimulating hormone (MSH)

D. parathyroid hormone (PTH)

E. vasoactive intestinal polypeptide (VIP)

[ArchivalUser]

bb

[ArchivalUser]

b-SIADH -small cell ca of lung.

[ArchivalUser]

bb

[ArchivalUser]

Explanation:

The correct answer is B. All of the hormones listed can be secreted by bronchogenic carcinoma, and may cause
a paraneoplastic syndrome. Of the answer choices provided, only ADH (antidiuretic hormone) causes
hyponatremia.

ACTH (choice A) causes Cushing's syndrome.

MSH (choice C) causes increased skin pigmentation.

PTH (choice D) causes hypercalcemia.

VIP (choice E) causes diarrhea and hypokalemia.

Other hormones that can be produced include human chorionic gonadotropin (hCG; gynecomastia), prolactin
(lactation), and calcitonin (hypocalcemia).