Differential Diagnosis

The patient's presentation of undetectable FSH and LH, low-normal prolactin, and low AMH, along with never having had a period and low estradiol, suggests a complex endocrine disorder. Here's a categorized differential diagnosis:

• Single Most Likely Diagnosis

  • Hypogonadotropic hypogonadism: This condition is characterized by low gonadotropin levels (FSH and LH) leading to inadequate stimulation of the ovaries, resulting in low estradiol levels and amenorrhea (never having a period). The low AMH (Anti-Müllerian Hormone) supports this diagnosis, as it indicates a reduced ovarian reserve or function.

• Other Likely Diagnoses

  • Congenital hypogonadotropic hypogonadism: Given the patient has never had a period, this could be a congenital condition affecting the hypothalamic-pituitary-gonadal axis.
  • Pituitary dysfunction: Although prolactin is within a relatively normal range, any issue affecting the pituitary gland could potentially disrupt FSH and LH production.
  • Gonadal dysgenesis: This condition involves abnormal development of the ovaries, which could explain the low AMH and estradiol levels, though typically FSH would be elevated in such cases unless there's a concomitant issue with gonadotropin production.

• Do Not Miss Diagnoses

  • Pituitary tumor (especially prolactinoma, despite the relatively low prolactin level): Even with a prolactin level of 2.7, which is not significantly elevated, a prolactinoma or other pituitary tumor could be suppressing FSH and LH production. Imaging of the pituitary gland is crucial.
  • Craniopharyngioma or other suprasellar tumors: These could compress the pituitary stalk or gland, affecting hormone production.
  • Autoimmune hypophysitis: An autoimmune inflammation of the pituitary gland could lead to deficiencies in pituitary hormones.

• Rare Diagnoses

  • Kallmann syndrome: A genetic disorder characterized by delayed or absent puberty and an impaired sense of smell, associated with hypogonadotropic hypogonadism.
  • Prader-Willi syndrome: A genetic disorder that can cause short stature, intellectual disability, and hypogonadism, among other features.
  • Resistant ovary syndrome: Although typically associated with elevated FSH, some forms could present with low FSH and LH due to ovarian resistance to gonadotropin stimulation.

The presence of HSV (Herpes Simplex Virus) positivity does not directly relate to the endocrine findings but is important for overall patient management and counseling regarding sexual health. Each of these diagnoses requires specific testing and evaluation to confirm, including genetic testing, imaging studies (like MRI of the pituitary gland), and further endocrine evaluations.