This document discusses pituitary tumors, their location in the pituitary gland near the optic chiasm, and their most common symptoms and signs. Pituitary tumors cause bitemporal hemianopia in 55% of cases due to compression of the optic chiasm from below. Diagnosis involves visual field testing and MRI imaging. Treatment options include surgery, medication, and radiation therapy depending on the type and size of the tumor. The majority of pituitary tumors are benign adenomas that can be treated with surgery or medication.

1. PITUITARY TUMORS

2. PITUITARY GLAND/HYPOPHYSIS
• Situated in sphenoid sinus.
• Depth sella 4-13mm,length 5-17mm
• Wt gland- 350-900mg

3. OPTIC CHIASMA
• Optic chiasma midline structure formed
by junction & partial decussation of
intracranial part of optic nerve.
• IT is ensheathed by pia & surrounded by
CSF.
• Lies over diahragma sellae- so PT VF
defect indicates suprasellar extention.
• Posteriorly chiasma continuous with optic
tracts & forms anterior wall of 3rd
ventricle.
• Nerve fibres arising from nasal half of
retina decussate at the chiasma.

4. PREFIXED - lies on tuberculum sellae, PT involve optic tract 1st(10%).
FIXED/CENTRAL CHIASMA - lies above sella, PT involve chiasma 1st (80%).
POST FIXED - dorsum sellae, PT damage optic nerve 1st (10%).

5. RELATIONS OF PITUITARY
GLAND
• Present above sphenoid sinus
• Medial- cavernous sinus
• Posterior- ventral surface of brain stem.
• Superior- optic nerve intracranial part, optic chiasm,
hypothalamus.
• Space of 1-10mm between pituitary gland & visual
pathway.

6. PITUITARY TUMORS
55% OF CHIASMAL LESION
CLASSIFICATION
BENIGN PITUITARY ADENOMAS - MC ,2-27% , Seen after 4D
• Small ,encapsulated lesions within sella.
• Microadenoma <10mm
• Macroadenoma >10mm
INVASIVE ADENOMAS- which grow and invade adjacent skull base
structures and its meningeal coverings.
PITUITARY CARCINOMAS -very rare

7. PITUITARY APOPLEXY
• Sudden enlargement of a pituitary gland as a result from hemorrhage or infarction of a
pituitary adenoma.
C/F- acute headache, visual loss, ophthalmoplegia, facial pain, or facial numbness.
PREDISPOSING FACTORS –
• Pregnancy
• Estrogen therapy
• Sheehan’s syndrome
• DM
• Bleeding disorders
• Radiation therapy
• Trauma
• Rx-systemic corticosteroids and hormone replacement

8. SYMPTOMS- PITUITARY TUMORS
• Early stage- amenorrhea, galactorrhea, impotence & infertility
• Later- deterioration of vision- central , visual field loss-temporal,
difficult depth perception.
Visual symptoms absent in – cushing’s syndrome , acromegaly.

9. SIGN
• Bitemporal hemianopia- hallmark pituitary macroadenoma.
• Maybe peripheral, central or both with or without splitting of
macula.
• Mc- upper quadrant
• RE- defect progress clockwise
• LE- counter clockwise
• Asymmetrical
• ocular CN palsy
• Papilledema- compression 3rd ventricle
• Seesaw nystagmus-which one eye elevates and
intorts while the other eye synchronously
depresses and extorts, then alternates

10. BITEMPORAL HEMIANOPIA
• Bitemporal hemianopia is a visual defect due to a lesion involving optic chiasm.
• While afferent sensory inputs from superior temporal quadrant of visual field are relayed through
inferior nasal fibers of optic nerve, the inputs from inferior temporal quadrant are relayed
through superior nasal fibers. Similarly the visual information from superior nasal quadrant and
inferior nasal quadrant are relayed through inferior temporal fibers and superior temporal fibers
respectively.
• Optic chiasm is an anatomical structure in middle cranial fossa formed by decussation of nasal
fibers of optic nerve travelling from retina to visual cortex.
• A lesion involving optic chiasm either due to compression or vascular compromise, disrupts nasal
fibers of optic nerve almost always resulting in bilateral defects in temporal half of visual field.
• Nasal fibers have predilection for greater pressure due to compression causing them to be easily
disrupted(Mechanical theory).
• A lesion compressing the chiasm from below (eg: pituitary tumors) will have predominant defects
in superior temporal quadrants along with partial defects in the inferior temporal quadrant and
Vice-versa.

12. OPTIC ATROPHY
• Bow tie pattern also may be a late sign of chiasmal compression
• Cause-fibers nasal to the macula are damaged, only the nasal and
temporal optic disc may be atrophic.
• Poor postoperative visual acuity.

13. DIAGNOSIS
Visual Field defect
Monocular Visual Field Deficits
• Asymmetric tumors involve one side of the
chiasm or an optic nerve.
• MC- supertemporal quadrantanopsia.
• Incidence 9%
• Symptoms- sudden monocular visual loss
• Cause-pituitary apoplexy, pituitary
adenoma.

14. CHIASMAL FIELD DEFICITS
• Bitemporal hemianopia.
• Pituitary adenomas, grow upward from
the pituitary stalk, compress the chiasm
from below, involves the inferior, nasal,
and macular nerve fibers.
• This corresponds to superior,
bitemporal, and central vision loss.
• Vison loss due to compression first
affects the superotemporal visual fields,
then inferotemporal, inferonasal and
finally superonasal fields.

15. Optic Tract
• Rare
• homonymous hemianopsia.
• RAPD +

16. NEUROIMAGING
• MRI - study of choice for most sellar and parasellar lesions.
• HRCT - when planning surgical resection of lesions.

17. Other Diagnostic Tests
• Complete endocrinological evaluation
• Lumbar puncture - inflammatory or infectious.
• Magnetic resonance angiography or cerebral angiography - vascular
cause or cavernous sinus invasion.

18. DIFFERENTIAL DIAGNOSIS
• Sectoral retinitis pigmentosa.
• Tilted optic disc
• Papilledema with greatly enlarged blind spots may cause bilateral
temporal field loss.

19. SYSTEMIC ASSOCIATIONS
• Frontal Headache- pituitary adenomas, pituitary apoplexy and
meningiomas.
• Pituitary endocrine dysfunction symptoms and signs - thick lips,
enlarged eyebrows, increased hand and feet size, large tongue,
diabetes mellitus and hypertension are common in acromegaly.
• Cushing’s disease-Amenorrhea galactorrhea syndrome in women and
impotence in men are typical features of prolactin producing tumors,
full-moon face and centripetal obesity,

20. PATHOLOGY
Pituitary Adenomas
• Adenomas arise as a discrete nodule from the anterior part of the
gland, called adenohypophysis.
• soft
• Color- grey white to pink or red, depending on the degree of
vascularity.

21. FUNCTION
• Prolactin-prolactinomas.
• ACTH-Cushing’s
disease.
• GH- acromegaly & gigantism.
•TSH- hypothyroid

22. TREATMENT, COURSE, AND OUTCOME
Pituitary Adenomas
• Surgery is the first line of treatment for most symptomatic pituitary
adenomas.
• Medical treatment - bromocriptine or cabergoline.
• Bromocriptine shrinkage of tumor volume and reduction in serum
prolactin may occur within days, and maximal shrinkage in tumor size
appears to be obtained within 6 weeks.
• Improvements in visual acuity and field defect improvement with
bromocriptine therapy in 80%–90% of patients.

23. SURGICAL TREATMENT
• Transsphenoidal approach can be used for 95% of pituitary tumors.
• Endoscope provides panoramic magnified views of the sellar
anatomy during both the approach and the resection of tumors itself.
• Craniotomy - invasive pituitary adenomas

24. RADIATION THERAPY
Indication
• Incompletely resected tumors.
• unresponsive to hormone therapy.
• Dose- not exceed 200 cGy daily because of the increased incidence of
radionecrosis.

25. REFERENCES
• AAO- NEURO OPHTHALMOLOGY
• ARAVIND EYE CARE- NEURO OPHTHALMOLOGY
• MYRON YANOFF

26. THANK YOU