Pituitary Microadenoma

1. A D E W I J A Y A , M D
M A R C H 2 0 1 9
Pituitary Microadenoma

2. Introduction
 Benign tumor of pituitary
 Size < 10 mm
 90 % non-functional
 Incidentalomas
 10 %  causing hormonal problems

3. Pathogenesis
 Mostly sporadic
 MEN 1
 Monoclonal

4. Clinical Presentation
 Nonsecreting incidentalomas  no symptoms
 Prolactinoma 
Asymptomtic in slightly elevated hormone
In Women: galactorrhea, oligorrhea/amenorrhea,
decreased libido, or infertility
In Men: hypogonadism, erectile dysfunction, and
decreased libido, galactorrhea (rare)

5. Clinical Presentation
 Corticotropin-secreting adenomas cause Cushing
disease.
 Growth hormone–secreting adenomas cause
acromegaly.
 Thyroid-stimulating hormone (TSH)–secreting
adenomas  hyperthyroidism
 Gonadotropin-secreting adenomas (rare) 
amenorrhea and a mismatch between estrogen and
gonadotropin levels

6. Diagnosis
 If no specific signs or symptoms  check prolactin
level (+IGF-1 level)
 If clinical suspicion of Cushing syndrome,
acromegaly, or other hormone excess exists, order
appropriate tests
 Screening tests for Cushing syndrome, such as
overnight dexamethasone suppression test, 24-hour
urinary free cortisol, or midnight salivary cortisol
 Brain MRI (contrast enhancement  secreting)

8. Management
 Prolactinoma: bromocriptine and cabergoline
 Acromegaly: surgical, alternative: long acting
somatostatin analogues, carbegoline, growth-
hormone receptor antagonist
 Cushing syndrome: surgical, alternative: a new long-
acting somatostatin agonist pasireotide, a
glucocorticoid receptor antagonist mifepristone, or
adrenal steroidogenesis inhibitors such as
ketoconazole

9. Management
 Prolactinoma: medical
 Other secreting tumors: surgical – transsphenoid or
gamma knife for recurrent tumors
 Non-secreting: observation. Serial MRI still
controversy
 Endocrinologist consultation in patients with
hormonal problems

10. Summary
 Benign pituitary tumor < 10 mm
 Non secreting vs secreting
 Non secreting  asymptomatics – no treatment
 Secreting: prolactinoma (most common)
 Treatment:
- Prolactinoma: medication (bromocriptine or
carbegoline)
- Other secreting tumors: surgical and endocrinologist
consultation

11. R E F E R E N C E S :
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