Prolactinoma is a benign tumor in the pituitary gland that causes increased production of prolactin. Prolactin is the hormone that stimulates the breasts to produce milk during pregnancy and breastfeeding.
High prolactin levels are known as hyperprolactinemia. This can cause symptoms such as irregular periods, missed periods, infertility, and erectile dysfunction.
Prolactinoma is diagnosed with blood tests that measure prolactin levels and imaging tests, such as MRI or CT scans. Treatment should be recommended by an endocrinologist or neurologist based on the tumor’s characteristics, and usually involves medication to regulate prolactin levels and relieve symptoms.
Common symptoms
The main symptoms of prolactinoma are:
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Breast milk production without being pregnant or having recently given birth (galactorrhea)
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Irregular periods or missed periods
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Pain during sex due to vaginal dryness
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Oily skin, which can contribute to acne
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Infertility
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Erectile dysfunction
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Breast enlargement in males (gynecomastia)
Symptoms of prolactinoma are mainly related to high prolactin levels.
High prolactin, or hyperprolactinemia, can also occur due to other conditions, such as hypothyroidism, pregnancy, breastfeeding, kidney failure, or the use of certain medications, so it is important to consult a doctor.
Main types
According to its size, this benign tumor can generally be classified into two main types:
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Microprolactinoma, which is smaller than 10 mm in diameter
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Macroprolactinoma, which is 10 mm or larger in diameter
It is important to identify the type of prolactinoma so the doctor can recommend the most appropriate treatment.
Possible causes
Prolactinoma occurs due to changes in how the pituitary gland works, leading to increased prolactin production and tumor formation. It is more common in females. However, the causes of pituitary gland dysfunction are not yet fully understood.
Confirming a diagnosis
Prolactinoma should be diagnosed by a primary care provider or endocrinologist based on symptoms and blood prolactin levels. Prolactin levels are usually higher in larger tumors, but values can vary and are not used alone to classify the tumor.
According to the Pituitary Society, an MRI is recommended to evaluate patients with high prolactin levels when no other cause is identified, as it helps detect and assess pituitary tumors. CT scans may be used as an alternative when MRI cannot be performed.
Additional tests, such as bone density scans, may be recommended in cases of long-term hormone imbalance. An echocardiogram may be considered in specific situations, especially for people using certain medications long-term.
Treatment options
Treatment for prolactinoma should be guided by an endocrinologist or primary care provider. According to the Pituitary Society, cabergoline is generally the preferred medication because of its efficacy and tolerability, although bromocriptine may also be used. Treatment aims to lower prolactin levels and relieve symptoms.
In some cases, surgery may be recommended to remove the tumor, especially when the tumor is large, causes symptoms such as vision problems, or does not respond to medication. Surgery may also be considered if medications are not well tolerated.
Radiation therapy may be used in rare cases when the tumor does not respond to medication or surgery, to help control tumor growth and prevent disease progression.