A 32-year-old woman presents with a 3-month history of amenorrhea, galactorrhea, and weight gain. Five months ago, she was started on clozapine 300 mg daily for schizophrenia. She has a known history of hypothyroidism but reports non-adherence with levothyroxine for the past 6 months. Vital signs are stable. Visual fields are intact to confrontation. Laboratory studies show: TSH 18.2 μU/mL (normal 0.4–4.0), free T4 0.6 ng/dL (normal 0.8–1.8), prolactin 92 ng/mL (normal <25), and LH/FSH are at the lower limit of normal. Pituitary MRI shows normal gland size with no focal lesion. Which of the following best explains her galactorrhea and menstrual disturbance?
- A)Clozapine-induced dopamine antagonism causing elevated prolactin
- B)Primary prolactinoma with incidental hypothyroidism
- C)Untreated hypothyroidism causing TRH-mediated prolactin elevation and secondary hypogonadismGABARITO
- D)Ectopic prolactin-secreting tumor in the adrenal gland
- E)Thyrotroph pituitary adenoma with co-secretion of prolactin
Explicação
Untreated hypothyroidism is the primary driver of hyperprolactinemia in this patient. Severe hypothyroidism (TSH 18.2) leads to elevated TRH (thyrotropin-releasing hormone), which stimulates both TSH and prolactin secretion. Additionally, hypothyroidism impair... Ver explicação completa e trilha adaptativa →