Forbes-Albright syndrome

Overview

Forbes-Albright Syndrome is a rare endocrine disorder characterized by amenorrhea (absence of menstruation), galactorrhea (inappropriate lactation), and hormonal imbalances due to a pituitary adenoma or other lesion affecting the pituitary gland. It is primarily seen in women and results from excessive secretion of prolactin, often in conjunction with deficiencies in gonadotropins (LH and FSH). This syndrome highlights the close relationship between pituitary tumors and reproductive hormone regulation.

Causes

The most common cause of Forbes-Albright Syndrome is a prolactin-secreting pituitary adenoma (prolactinoma), a benign tumor of the anterior pituitary gland. Other potential causes include:

• Non-functioning pituitary adenomas compressing normal pituitary tissue

• Craniopharyngiomas or other sellar masses

• Trauma, surgery, or radiation involving the pituitary gland

• Hypothalamic dysfunction disrupting prolactin regulation

• Certain medications that increase prolactin levels (e.g., antipsychotics, antidepressants)

Symptoms

Symptoms of Forbes-Albright Syndrome primarily result from elevated prolactin levels and reduced gonadotropin secretion. Common signs and symptoms include:

Reproductive and Hormonal Symptoms

• Amenorrhea or oligomenorrhea (absent or irregular menstruation)

• Galactorrhea (milk production not associated with childbirth or breastfeeding)

• Infertility

• Loss of libido

• Vaginal dryness

Neurological Symptoms (if tumor is large)

• Headaches

• Visual disturbances, such as bitemporal hemianopia (loss of peripheral vision)

Diagnosis

Diagnosis of Forbes-Albright Syndrome involves hormonal assays and imaging studies. Key steps include:

• Serum prolactin measurement: Elevated prolactin levels confirm hyperprolactinemia.

• LH and FSH levels: Typically low or inappropriately normal in the context of amenorrhea.

• Thyroid function tests: To rule out hypothyroidism as a cause of elevated prolactin.

• MRI of the pituitary gland: To identify and characterize pituitary adenomas or other sellar masses.

• Ophthalmologic evaluation: If visual symptoms are present, to assess optic chiasm involvement.

Treatment

Treatment of Forbes-Albright Syndrome is directed at the underlying cause, typically a prolactinoma. Options include:

• Dopamine agonists (e.g., bromocriptine, cabergoline): First-line therapy to reduce prolactin levels and shrink tumors.

• Transsphenoidal surgery: For patients who are resistant to medical therapy or have large tumors causing mass effect.

• Radiation therapy: Considered in refractory cases or when surgery is not feasible.

• Hormone replacement therapy: May be needed if pituitary hormone deficiencies are present.

Prognosis

The prognosis for individuals with Forbes-Albright Syndrome is generally favorable with appropriate treatment. Most patients respond well to dopamine agonists, which can restore menstrual function, resolve galactorrhea, and reduce tumor size. Long-term monitoring is essential, as recurrence of symptoms or tumor regrowth may occur. Early diagnosis and consistent management are key to preserving endocrine function and quality of life.