Differential Diagnosis for Elevated Prolactin in a 23-Year-Old Woman
Single Most Likely Diagnosis
- Stress or Physiological Causes: Elevated prolactin levels can be caused by stress, sleep deprivation, or physical exertion. Given the patient's age and presentation with irregular periods, but otherwise normal hormone levels, a physiological or stress-related cause is plausible.
Other Likely Diagnoses
- Prolactinoma: A benign tumor of the pituitary gland that secretes prolactin. It's a common cause of elevated prolactin levels and can lead to irregular menstrual periods.
- Hypothyroidism (despite normal screening): Although the patient's thyroid function tests are normal, hypothyroidism can sometimes cause elevated prolactin levels. It's possible that the patient has a mild or subclinical form of hypothyroidism not detected by initial screening.
- Polycystic Ovary Syndrome (PCOS): While PCOS is often associated with hormonal imbalances, some patients may have normal FSH, LH, and estradiol levels. Elevated prolactin can be seen in some cases of PCOS, contributing to irregular periods.
Do Not Miss Diagnoses
- Pituitary Macroadenoma: A larger tumor of the pituitary gland that can cause elevated prolactin levels and compress surrounding structures, leading to serious complications if left untreated.
- Cranial Injury or Mass: Any mass or injury affecting the pituitary stalk or hypothalamus can disrupt normal prolactin regulation, leading to elevated levels.
- Medication-Induced Hyperprolactinemia: Certain medications, such as antipsychotics, antidepressants, and blood pressure medications, can cause elevated prolactin levels as a side effect.
Rare Diagnoses
- Acromegaly: A condition caused by excess growth hormone production, which can sometimes be associated with elevated prolactin levels.
- Thyrotropin-Releasing Hormone (TRH) Producing Tumor: A rare type of tumor that secretes TRH, leading to elevated prolactin and thyroid hormone levels.
- Idiopathic Hyperprolactinemia: A condition where elevated prolactin levels are present without any identifiable cause, which is rare but can occur.