L E W I S S . B L E V I N S , J R . , M . D .

C A L I F O R N I A C E N T E R F O R P I T U I T A R Y D I S O R D E R S A T U C S F

Endocrine Evaluation of the Patient with a

Sellar Mass

Sellar Masses

What are the potential endocrine consequences of a sellar mass?

  Abnormalities of pituitary hormone secretion   Excess   Deficiency

  Normal pituitary function   Diabetes insipidus

  Suggests a disease process other than a pituitary adenoma

Pituitary Excess

  Hyperprolactinemia   Acromegaly   Cushing’s Syndrome   Hyperthyroidism

Each of these disorders are associated with important co-morbidities that often require evaluation.

Hyperprolactinemia

  Serum PRL level   Macroadenoma and PRL > 200 ng/mL is almost

always a prolactinoma   Atypical prolactinomas often associated with PRL <

200 ng/mL   Microadenomas can be associated with any degree of

PRL elevation   Stalk and drug-induced hyperprolactinemia usually

see PRL < 150 ng/mL.   Exclude pregnancy!!!!

Acromegaly

  IGF-1 level almost always elevated   GH levels not diagnostic but indicative of disease

activity   Oral glucose suppression test occasionally used to

confirm abnormal GH secretion

Cushing’s Syndrome

  24-h Urine Free Cortisol   Plasma ACTH level   Other tests under guidance of an Endocrinologist

Hyperthyroidism

  TSH, free T4 and T3 levels   TSH usually elevated but may be inappropriately

“normal” in setting of hyperthyroidism

Pituitary Insufficiency

  Partial or complete loss of one or more anterior pituitary hormones

  Presentation can range from asymptomatic to severe hyponatremia and prostration

  Pituitary deficiency leading to target gland deficiencies   T4 and T3 (Central Hypothyroidism)   Cortisol (Central Adrenal Insufficiency)   Sex Steroids (Central Hypogonadism)   GH deficiency   PRL deficiency

Central Hypothyroidism

  Low or low normal free T4 and T3 do to lack of trophic stimulus

  TSH levels low in 8%, high in 8%, and normal in 84% of patients

Central Adrenal Insufficiency

  Failure of the adrenal glands to produce cortisol due to lack of trophic stimulus

  8AM Cortisol low or low normal and ACTH levels variable

  ACTH stimulation test or insulin-induced hypoglycemia test to confirm diagnosis

Central Adrenocortical Insufficiency 8 AM Serum Cortisol levels

Cortisol Sensitivity Specificity

Central Hypogonadism

  Failure of the pituitary to stimulate gonadal function

  Abnormal menses in women

  Inappropriately normal or low LH and FSH levels in setting of low Estradiol in postpubertal or postmenopausal women

  Inappropriately normal or low LH levels and a low total or free testosterone in men

Growth Hormone Deficiency

  IGF-1 low in setting of other hormone deficits is of 70% accuracy

  Stimulation test required to confirm diagnosis

Suggested tests

  PRL   IGF-1, GH   TSH, free T4, T3   Cortisol, ACTH   24-h Urine Free Cortisol if Cushing’s suspected   LH and Testosterone in men   FSH and Estradiol in women with absent or

abnormal menses   Serum sodium and urine osmolarity if DI suspected

Pituitary Hyperplasia

  Primary hypothyroidism   Menopause   Primary hypogonadism in men   Lactotroph hyperplasia   Addison’s Disease