3. Did you know??
• Robert Wadlow was
the tallest recorded
man on earth at a
height of 8 ft 11 in.
• His astounding
height was the
result of a pituitary
tumor
4. Anatomy
• Located immediately
under the hypothalamus
• Rests on the Pituitary
fossa (sella turcica)
• Comprised of two lobes;
anterior
(adenohypohpysis) and
posterior
(neurohypophysis)
• The lobes are
separated by an
intermediate lobe
5. Function
• This organ is part of the endocrine system
• Once thought of as the “master gland” the
pituitary gland is actually controlled by the
hypothalamus
• Sends many
hormones to
glands
throughout the
body
6. PITUITARY ADENOMA
• Pituitary adenomas are a collection of
tumors that arise from the pituitary gland.
They are the most common cause of
Optic chiasm compression. Ophthalmologic
pathology typically involves
Visual field defects, although less commonly
patients may also have Ocular motility
deficits and/or Diplopia, certain forms
of Nystagmus, signs and symptoms
of Increased intracranial pressure due to
mass effect, Optic atrophy.
9. PITUITARY ADENOMA(BASOPHIL)
• Basophil tumours secrete ACTH and cause
Cushing disease
• (Cushing syndrome refers to the clinical
picture due to any cause of increased blood
cortisol).
10. SIGNs
a Obesity may be generalized or
classically involve the trunk, abdomen
and neck (‘buffalo hump’).
b The face is swollen (‘moon face’)
females may be hirsute
c The skin is thin and susceptible to
bruising. Purple striae may be seen
Hyperpigmentation may develop with
ACTH-dependent Cushing syndrome
d Other features
depression/psychosis, osteoporosis,
slow wound healing and proximal
myopathy.
11. Ophthalmic features
• Bitemporal hemianopia is uncommon with
secreting pituitary adenomas, which tend to
present with systemic features of
hypersecretion,
• As opposed to non-secreting pituitary
tumours, which tend to present with chiasmal
compression
13. INVESTIGATION
• In Cushing syndrome are targeted at first
establishing the presence of elevated cortisol
levels
• then identifying the underlying cause (unless
iatrogenic); they are best undertaken by an
endocrinologist.
14. TREATMENT
• a Surgical removal of pituitary adenoma
or adrenal secreting tumour. Ectopic foci of
ACTH secretion may also be amenable to
excision.
•
b Medical suppression of cortisol
secretion with metyrapone or
aminoglutethimide.
15. PITUITARY ADENOMA(ACIDOPHILIC)
• Acidophil tumours cause gigantism in children
and acromegaly in adults.
• Acromegaly is caused by excessive growth
hormone (GH) occurring during adult life,
after epiphyseal closure and is almost
invariably due to a secreting pituitary
acidophil adenoma (hypersecretion of growth
hormone in childhood, prior to epiphyseal
closure, results in gigantism).
16. SIGNs
• a Skin. Hyperhidrosis, acne and
hirsutism in females.
b Face • thick lips, exaggerated
nasolabial folds, prominent supraorbital
ridges
• Enlargement of the jaw with dental
malocclusion
c Enlargement of the head hands,
feet, tongue and internal organs.
17. Ophthalmic features
• a Common. Bitemporal hemianopia and
optic atrophy.
b Rare. Angioid streaks and see-saw
nystagmus of Maddox.
18. INVESTIGATION
• The diagnosis may be confirmed by
measuring GH levels in response to an oral
glucose tolerance test.
• Normal individuals manifest suppression of
GH levels to below 2mU/L. However, in
acromegaly, GH levels do not fall, and may
paradoxically rise.
19. TREATMENT
• Treatment options include
• Bromocriptine (a long-acting dopamine
agonist),
• Radiotherapy (external beam or by
implantation of yttrium rods in the pituitary)
and
• Trans-sphenoidal hypophysectomy.
20. PITUITARY
ADENOMA(CHROMOPHOBE)
• Chromophobe adenomas may secrete
prolactin and are referred to as
prolactinomas
• in men they cause hypogonadism,
impotence, sterility, decreased libido, and
occasionally gynaecomastia
• Chromophobe adenoma is the most common
primary intracranial tumour to produce neuro-
ophthalmological features.
21. PRESENTATION
• Head ache due to involvement of pain-sensitive
fibres in the diaphragma sellae
• Visual field defects depend on the anatomical
relationship between the pituitary and chiasm. • If
the chiasm is central, both superotemporal fields are
affected first, as the tumour grows upwards and
splays the anterior chiasmal notch, compressing the
crossing inferonasal fibres
• The defects then progress into the lower
temporal fields. As tumour growth is often
asymmetrical, the degree of visual field loss is usually
different on the two sides.
• Patients may not present until central vision is
affected from pressure on the macular fibres.
22. • Optic atrophy is present in approximately 50% of
cases with field defects caused by pituitary lesions
• Extensive loss of the temporal visual field in both
eyes can disrupt sensory fusion, decompensate a
phoria or cause problems with near vision.
‘Postfixation blindness’ refers to the presence of a
blind area distal to the fixation point.
• Miscellaneous features include diplopia as a result
of lateral expansion into the cavernous sinus and
involvement of ocular motor nerves and, rarely, see-
saw nystagmus
23.
24. Special investigations of pituitary
adenomas
• MR demonstrates the relationship between a
mass lesion and the chiasm
• CT will demonstrate enlargement or erosion
of the sella
• Endocrinological evaluation All patients
suspected of having a pituitary adenoma
should have assays of serum prolactin, FSH,
TSH and growth hormone
25.
26. Prevention
There are no known ways to prevent pituitary cancer, but
there are ways to lower your chances of getting any kind
of cancer, and to kill it early if you do get cancer. Such
methods include:
1. Know your family’s health history, and take note of any
signs that could be a sign of cancer.
2. Eat well, and stay active.
3. Avoid extensive exposure to harmful substances such as
chemicals and even the sun.
