Differential Diagnosis for a 17-year-old Female with Irregular Periods
Single Most Likely Diagnosis
- Polycystic Ovary Syndrome (PCOS): The patient's irregular periods, elevated androgen levels (DHEAS 112,17-hydroxyprogesterone 93, androstenedione 233, testosterone 46), and normal prolactin and thyroid function tests are consistent with PCOS. The slightly elevated prolactin level is not uncommon in PCOS patients.
Other Likely Diagnoses
- Non-classic Congenital Adrenal Hyperplasia (NCAH): The elevated 17-hydroxyprogesterone level suggests the possibility of NCAH, although the androstenedione level is also elevated, which is more typical of PCOS.
- Hyperandrogenism due to other causes: Other causes of hyperandrogenism, such as androgen-secreting tumors or Cushing's syndrome, are less likely given the patient's normal cortisol and ACTH levels.
Do Not Miss Diagnoses
- Cushing's Syndrome: Although the patient's cortisol level is normal, Cushing's syndrome can present with irregular periods and hyperandrogenism. It is essential to consider this diagnosis due to its potential severity and the need for prompt treatment.
- Androgen-secreting tumor: A tumor secreting androgens, such as an ovarian or adrenal tumor, could cause the patient's symptoms and should not be missed due to the potential for malignancy.
Rare Diagnoses
- Congenital Adrenal Hyperplasia (CAH) due to 21-hydroxylase deficiency: Although less likely, CAH due to 21-hydroxylase deficiency could present with hyperandrogenism and irregular periods. The patient's 17-hydroxyprogesterone level is elevated, but not to the extent typically seen in classic CAH.
- Other rare causes of hyperandrogenism: Other rare causes, such as hyperandrogenism due to insulin resistance or other genetic disorders, are possible but less likely given the patient's presentation.