Which of the following would be an example of ectopic hormone production?

Which of the following would be an example of ectopic hormone production?

• A. Prolactin production by pituitary tumors
• B. Calcitonin production by thyroid tumors
• C. Growth hormone production by lung tumors
• D. Cortisol production by adrenal tumors

Answer: (C)

Ectopic hormone production occurs when tissue outside the normal endocrine gland starts secreting a hormone. In this case, a lung tumor secreting growth hormone fits that pattern because growth hormone is normally produced by the pituitary gland, not the lungs. The tumor in the lung releases GH independently of pituitary control, leading to hormone excess without a pituitary source. The other examples involve hormones produced by the gland where that hormone normally resides (prolactin from the pituitary, calcitonin from the thyroid, cortisol from the adrenal cortex), so they are not ectopic.

Ectopic hormone production occurs when tissue outside the normal endocrine gland starts secreting a hormone. In this case, a lung tumor secreting growth hormone fits that pattern because growth hormone is normally produced by the pituitary gland, not the lungs. The tumor in the lung releases GH independently of pituitary control, leading to hormone excess without a pituitary source.

The other examples involve hormones produced by the gland where that hormone normally resides (prolactin from the pituitary, calcitonin from the thyroid, cortisol from the adrenal cortex), so they are not ectopic.