Professional and Linguistic Assessments Board (PLAB) Practice Exam

What does it indicate if there is no pituitary gland visible on an MRI?

1. Empty sella

2. Hypopituitarism

3. Pituitary adenoma

4. Craniopharyngioma

The correct answer is: Empty sella

The presence of no visible pituitary gland on an MRI is indicative of an empty sella syndrome, which occurs when the sella turcica, the bony structure that houses the pituitary gland, is filled with cerebrospinal fluid instead of the gland itself. This can happen due to various reasons, including prior surgery, radiation, or the presence of a congenital condition where the pituitary gland is absent or small. In cases of empty sella syndrome, the pituitary stalk may appear intact, and other pituitary functions can remain normal, though sometimes there can be associated hormonal deficiencies. This condition is often asymptomatic and discovered incidentally when imaging is done for other reasons. In contrast, hypopituitarism refers to a clinical condition marked by decreased hormone production, which might or might not show a visible gland depending on the underlying cause. A pituitary adenoma is typically characterized by an enlarged pituitary gland and often would still show some residual pituitary tissue on imaging. Craniopharyngiomas, which are tumors near the pituitary gland, can affect its visibility but would usually present with changes or displacement in surrounding structures rather than a completely empty sella appearance.