Differential Diagnosis for Hyperprolactinaemia, Oligomenorrhoea, and Hyperandrogenism
Single Most Likely Diagnosis
- Polycystic Ovary Syndrome (PCOS): This condition is the most common endocrine disorder in women of reproductive age and is characterized by hyperandrogenism, ovulatory dysfunction (often presenting as oligomenorrhoea), and polycystic ovaries on ultrasound. Hyperprolactinaemia can also be present in some cases of PCOS, either as a primary condition or secondary to the hormonal imbalance.
Other Likely Diagnoses
- Prolactinoma: A type of pituitary tumor that secretes prolactin, leading to hyperprolactinaemia. This can cause oligomenorrhoea or amenorrhoea due to the inhibitory effect of prolactin on gonadotropin-releasing hormone (GnRH) secretion. Hyperandrogenism might not be a direct effect but can be seen in association with other conditions.
- Other pituitary disorders (e.g., pituitary insufficiency or other types of pituitary tumors): These can lead to hormonal imbalances, including hyperprolactinaemia and disturbances in the gonadal axis, resulting in oligomenorrhoea and potentially hyperandrogenism.
- Congenital Adrenal Hyperplasia (CAH): Although more commonly diagnosed in infancy, mild forms of CAH can present later with symptoms of hyperandrogenism and irregular menstrual cycles. Hyperprolactinaemia is not a primary feature but can be associated in some cases.
Do Not Miss Diagnoses
- Cushing's Syndrome: This rare endocrine disorder is caused by excess cortisol and can lead to hyperandrogenism, oligomenorrhoea, and potentially hyperprolactinaemia due to the disruptive effect of cortisol on the hypothalamic-pituitary axis. It's crucial to diagnose Cushing's Syndrome due to its significant impact on morbidity and mortality if left untreated.
- Thyroid disorders: Both hypothyroidism and hyperthyroidism can affect menstrual regularity and may be associated with hyperprolactinaemia. Although they are not primary causes of hyperandrogenism, their impact on overall hormonal balance makes them important to consider.
Rare Diagnoses
- Nelson's Syndrome: A rare condition that occurs in some individuals after bilateral adrenalectomy for Cushing's Syndrome, characterized by a pituitary tumor (usually an aggressive corticotrophin-producing tumor) that can lead to hyperprolactinaemia among other hormonal disturbances.
- Other rare genetic disorders (e.g., hyperandrogenism due to 3-beta-hydroxysteroid dehydrogenase deficiency): These can present with hyperandrogenism and may have associated menstrual irregularities and hyperprolactinaemia, though they are much less common than PCOS or prolactinoma.