Prolactinoma

What is prolactin ?

Prolactin is a hormone secreted by the anterior pituitary gland which maily plays a significant role in helping milk secretion in the postpartum period.

What causes prolactin levels to be raised ?

There are three main causes:

  1. Drugs like Metoclopromide, Chlorpromazine, anti depressants like Amitriptyline & Fluoxitene
  2. Underactive thyroid gland
  3. Prolactinomas – Prolactin-producing tumour of the pituitary gland. Prolactinomas occur most commonly in those under 40 years old. They are rare in children. These tumors are about fives times as common in women as men. These tumors account for at least 30% of all pituitary adenomas

What are the symptoms ?

In women

  • Cessation of menses not related to menopause
  • Abnormal milk flow from the breast not related to nursing or childbirth (galactorrhea)
  • Infertility
  • Decreased sexual interest
  • Headache
  • Visual changes

In men

  • Enlargement of breast tissue (gynecomastia)
  • Infertility
  • Impotence
  • Decreased sexual interest
  • Headache
  • Visual changes

Large Prolactinoma

Large tumour, can cause pressure symptoms such as headache or visual problems. This is because the nerves to the eyes pass over the top of the pituitary gland. In a minority of patients, an increase in pituitary size may cause pressure on these nerves and produce visual disturbance.

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What are the Investigations that will be required ?

1. Blood sample for

  • Thyroid function test
  • Prolactin levels ( Single values may be inconclusive three pooled samples might be required at times)
  • Other Pituitary hormones

2. Visual field testing
3. MR scan of the brain
4. Women who have not had periods for a year, and male patients should be offered bone density tests to ensure that they are not developing osteoporosis

What is the treatment ?

These are the most important pituitary tumors as the can be managed without surgery.

  • Most patients are treated with:
  • Bromocriptine (one tablet (2.5mg) twice or three times a day).
  • Cabergoline long acting and requires one or two doses(0.5mg) per week
  • Prolactin levels often fall to normal within a few weeks of starting the treatment. In women, once prolactin has fallen to normal, menstrual cycles usually resume, interest in sex is regained and fertility is restored in most cases. In men, testosterone levels may rise to normal, which brings an improvement in sex life.
  • Rarely surgery is required when the tumors are resistant to treatment
  • These drugs are very safe during pregnancy and thousands of normal ‘Bromocriptine babies’ have been born.
  • Risk of tumor increasing in size during pregnancy is very remote.
  • Side effects of Bromocriptine are very minimal & include nausea, vomiting & constipation.

This article is prepared along with Dr Menaka