Sellar/ suprasellar tumors

General overview of the sellar supra-sellar tumors

1. Sellar /Supra- sellar tumors By: Dr Shaheer Anwar

2. Tumors of pituitary Gland constitute 5-10%of the intracranial tumors. They arise from the anterior portion of the gland and are usually benign. Pituitary adenomas. Cranipharyngiomas . Optic nerve ( Glioma ) Astrocytoma. Suprasellar meningioma. Meningioma of optic nerve sheath. Suprasellar epidermoid / dermoid .

3. Classification: Classic classification: Eosinophilic cells: Prolactin, Growth hormone. Basophilic cells: Adrenocorticotrophic hormone, thyroid stimulating hormone, Gonadotrophic hormones Chromophobe cells: Non functioning.

4. Present classification: Immuo-histochemical techniques permit a classification based on the hormone type secreted. GH secreting tumor. (20-25%) Prolactinoma . ( 25-50%) ACTH secreting tumor. (5-10%) TSH secreting tumor. (Rare) FSH/LH secreting tumor .(Rare) Inactive

5. Clinical presentation of the patients: Clinical presentation of the patients depends upon the size of the tumor and the type of the tumor. Depending upon the size tumors are divided into 2 types: Large tumors(macro-adenomas). Small tumors <1cm(micro-adenomas).

6. Coronal and saggital sections of pituitary microadenoma on MRI brain:

7. Coronal and saggital sections of pituitary macroadenoma on MRI brain:

8. Local Mass Effects: Headache. Visual field Defects: Pressure on the inferior aspect of the optic chiasma usually causes superior tempora l quadrantanopia initially, with progression to bitemporal hemianopia. Cavernous sinus compression: Lateral expansion compress the nerves lying within the cavernous sinus. vertical compression obstructs the foramen of munro causing hydrocephalus and hypothalamic compression.

9. Endocrine Effect: Hypersecretion : The clinical syndrome produced is dependent on the hormone secreted. Growth hormone: Excess GH secretion in adult causes Acromegaly. Excess secretion in childhood causes Gigantism. Prolactin: Infertility. Amenorrhea. Galactorrhea . ACTH: Excess secretion of ACTH causes all the features of the Cushing’s syndrome. Hyposecretion .

10. Investigations: X-ray Skull: Large tumors causes expansion or ballooning of the pituitary fossa or may erode the floor.

11. CT Scan Brain: CT brain with contrast enhancement is very useful in demonstrating the tumors expanding into the suprasellar compartment.

12. MRI: It gives more details regarding tumor extension and involvement of the vessels.

13. Hormonal profile: Cortisol levels. TSH, T3, T4 levels. FSH/LH levels. Prolactin levels.

14. Management: Drug Therapy: Dopamine agonists lower th abnormal concentrations and the tumor shrinks agents include bromocriptine and carbergoline . Somatostatins analogues e.g. octreotide . GH receptor antagonists e.g. pegvisomant . Operative Approach: From below: Transphenoidal approach is through incisions: Sublabial incision Transnasal endoscopic approach. From above: F rontal craniotomy. This approach is reserved for large frontal and lateral extensions. Radiotherapy: P ituitary adenomas are radiosensitive and external irradiation is commonly employed. Stereotactic surgery is also used. Radioactive seeds of yttrium or gold are implanted in the pituitary fossa.

15. Treatment Selection: Treatment choice depends upon the P resenting problems and patient’s reuirements . Patient’s age. Preference and experience of the treatment centre .