**Core Concept**
Pituitary adenomas are benign tumors that arise from the pituitary gland, a small endocrine gland located at the base of the brain. These tumors can be functioning (secreting excess hormones) or non-functioning (non-secreting). The pituitary gland plays a crucial role in regulating various bodily functions, including growth and development, metabolism, and reproductive processes.

**Why the Correct Answer is Right**
Pituitary adenomas are more common in individuals with a family history of the condition, particularly in those with multiple endocrine neoplasia type 1 (MEN1) syndrome. The most common type of functioning pituitary adenoma is the prolactinoma, which secretes excess prolactin. Other types of functioning adenomas include growth hormone-secreting adenomas, adrenocorticotropic hormone (ACTH)-secreting adenomas, and thyroid-stimulating hormone (TSH)-secreting adenomas. Non-functioning adenomas, on the other hand, do not secrete excess hormones.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because pituitary adenomas are not typically associated with thyroid disorders.
**Option B:** This option is incorrect because while pituitary adenomas can cause hyperprolactinemia, they are not a primary cause of polycystic ovary syndrome (PCOS).
**Option C:** This option is incorrect because pituitary adenomas are not typically associated with adrenal gland disorders.

**Clinical Pearl / High-Yield Fact**
A key clinical feature of pituitary adenomas is their potential to cause visual disturbances due to compression of the optic chiasm. This can result in symptoms such as bitemporal hemianopsia (blindness in the outer half of each visual field).

**Correct Answer:** C.