Prolactinoma is the most common secretory Pituitary adenoma and arises through neoplastic transformation of the lactotroph cells of the anterior pituitary[^1]. Prolactinomas are characterized biochemically by an elevated prolactin level.
Diagnosis
The diagnosis of a prolactinoma is established on the basis of a persistent elevation of the serum level of Prolactin and radiological evidence of a pituitary adenoma, after other causes of hyperprolactinemia have been excluded[^3]. Macroadenomas are typically associated with prolactin levels of more than 250 µg\/L and may, in some cases, also reach levels above 1000 µg\/L [^3].
Treatment
Prolactinomas are usually treated medically with dopamine D2 agonists and do not require surgical intervention. In some cases, such as treatment failure or medication intolerance, surgical removal may be indicated.
Imaging
Differential diagnosis of elevated prolactin
Prolactin may be elevated for other reasons, such as:
Pregnancy: During pregnancy, the prolactin level may be elevated approximately 10-fold[^2].
Medications: Medications such as metoclopramide, phenothiazines, butyrophenones, or risperidone may increase prolactin levels to above 100 µg\/L[^2].
Stress: Physical and psychological stress can slightly increase prolactin secretion, but rarely to levels above 40 µg\/L [^2].
Compression: In macroadenomas, compression of the pituitary stalk may result in a slight elevation of prolactin levels to approximately 25-250 µg\/L[^3]. This phenomenon is also referred to as the stalk effect.