Makindo Medical Notes

Related Subjects: |Male Infertility |Prolactin |Prolactinoma |Sheehan's syndrome |Acromegaly and Giantism

Surgery is rarely needed and medication will usually suffice with an excellent prognosis

About

• Commonest secreting pituitary tumour
• Causing nearly 30% of pituitary tumour s.
• Female/Male x 10 male
• Prolactinomas are found at post mortem and are often clinically silent
• Usually treatable medically

Clinical

• Often none. silent until late. Often found at PM
• Galactorrhoea 90% of women and rare in men
• Amenorrhea, oligomenorrhea, reduced libido and infertility
• Long-term risk of low bone mineral density
• Hypogonadism as PRL suppresses testosterone level.
• Pituitary Tumour Mass Effects as described above may be seen

Investigations

• Fasting PRL: Normal Serum prolactin < 20 ng/mL or 20 µg/L or 625 mU/L in women and 375 mU/L in men. PRL high (Exclude macroprolactin) , testosterone low
• Pituitary MRI with Gadolinium shows microadenoma or macroadenoma
• Assess vision in those with suprasellar extension
• Assess biochemical pituitary function - see hypopituitarism
• Echocardiogram before starting Cabergoline

Differential

• Raised PRL due to Pregnancy, lactation, drugs
• Non secreting adenoma pressing on the stalk

Management

• Medical - The only pituitary tumour where medical treatment is usual.
• Dopamine agonists Bromocriptine or Cabergoline 0.5-1.0 mg per week (Dostinex) which is given twice weekly to shrink tumour and surgery is rarely required. The best predictor of reoccurrence on stopping is the presence of residual tumour on MRI. The risk of cardiac valvopathy appears to be low in prolactinoma patients on standard doses of cabergoline (< 2 mg/week).
• Transsphenoidal hypophysectomy rarely if medical treatment fails or radiotherapy can be useful or there is a large tumour interfering with vision. Malignant prolactinomas are very rare.