Pituitary Macroadenoma and Neuro-ophthalmic Syndrome

10 Questions

Which imaging modality is most suitable for evaluating bone structures in sellar masses?

Computed Tomography (CT)

What is the primary purpose of performing Magnetic Resonance Imaging (MRI) focused on the hypophyseo-hypothalamic system?

To diagnose pituitary adenomas and differentiate them from other sellar masses

Which of the following is NOT a characteristic of a lactotroph adenoma on laboratory evaluation?

Elevated cortisol levels after 1 mg Dexamethasone inhibition

What is the primary role of a 1 mg Dexamethasone suppression test in the diagnosis of endocrine disorders?

To diagnose Cushing's disease

Which imaging modality is most useful for detecting intratumoral calcifications in sellar masses?

Computed Tomography (CT)

What is the primary indication for performing a Sella Turcica X-ray Lateral Incidence in the diagnosis of sellar masses?

To evaluate the enlargement of the sella and wall erosion

Which of the following is a characteristic of a pituitary adenoma on laboratory evaluation?

Hormonal hypersecretion

Which of the following imaging modalities is NOT commonly used in the diagnosis of sellar masses?

Ultrasound

What is the primary purpose of performing an Oral Glucose Tolerance Test (OGTT) in the diagnosis of endocrine disorders?

To diagnose acromegaly

Which of the following is a characteristic of acromegaly on laboratory evaluation?

Elevated GH levels during OGTT

Study Notes

Neuro-ophthalmic Syndrome

Chronic, persistent, progressive headache with retroorbital and bitemporal localization can occur due to pituitary macroadenoma, which can disappear when the sellar diaphragm is perforated, but reappears when intracranial hypertension develops.
Acute headache accompanied by nausea, vomiting, and alteration of consciousness can occur due to sudden growth of pituitary as a consequence of infarction or hemorrhage inside a pituitary adenoma.

Visual Field Defects

Optic chiasm syndrome with bitemporal hemianopia can occur due to compression of nasal optic fibers at the optic chiasm level.
Other visual field defects can occur, such as scotomas, quadranopsies, uni- or bilateral sight loss, stasis, papillar edema, or retinal hemorrhages.

Cranial Nerve Compression

Compression of the oculomotor nerve, palsy of IV, V, and VI cranial nerves can cause ptosis, diplopia, ophthalmoplegia, and facial numbness.

Other Symptoms

Temporal lobe epilepsy (uncinate seizures) can occur due to parasellar extension of pituitary adenomas.
Anosmia and personality disturbances can occur due to frontal lobe involvement.
Hypothalamic compression can cause disturbances in temperature, sleep, appetite, or thirst regulation, and dysfunctions of the autonomous nervous system.

Incidentaloma

A pituitary tumor mass can be discovered incidentally during a cranial imagistic exploration for other reasons, and is called an "incidentaloma".

Hypothalamic-Pituitary Gland Unit

The hypothalamic-pituitary gland unit represents the paradigm of the interaction between the endocrine and nervous systems.

Anatomy

The hypothalamus forms the floor and lateral walls of the third ventricle.
The pituitary gland lies at the base of the skull in the sella turcica of the sphenoid bone.
The pituitary gland is surrounded by dura mater and has an opening of 5 mm for the pituitary stalk in the diaphragma sellae.

Laboratory Investigations

Laboratory investigations consist of plasma pituitary hormone levels determinations.
Hormonal hypersecretion is caused only by pituitary adenomas.
The demonstration of hormonal hypersecretion identifies the sellar mass as a pituitary adenoma and also identifies the type of adenoma.

Imagistic Investigations

Magnetic resonance imaging (MRI) is the single best imaging procedure for most sellar masses.
Computed tomography (CT) allows better visualization of bone structures.
Positron emission tomography (PET), scintigraphy with radioactive octreotid (octreoscan), or SPECT (single photon-emission computed tomography) can also be used.
Sella turcica X-ray lateral incidence can evidentiate the enlargement of the sella, wall erosion, double contour, dorsal wall verticalization, and clinoidal hypertrophy.