Abstract. Objective: Our purpose is report a case of primary hypothyroidism associated with hyperprolactinemia and pituitary macroadenoma. Background: We present the case report, including detailed laboratory and radiological findings in 28 year old woman. In primary hypothyroidism there is hyperplasia of both thyrotrophs and lactotrophs as a response to TRH hypersecretion. The hyperplasia can result in significant enlargement of the pituitary gland and can be mistaken for a prolactin-secreting tumor. Case: We report the case of a female patient who presented with amenorrhea of 7-months duration and was found by her gynecologist to have elevated prolactin. The initial MRI showed a 1.7 cm pituitary mass which was treated initially by cabergoline. Due to the patients noncompliance and lack of follow up, the patient remained on cabergoline for 6 months and did not do thyroid function tests. Finally, after 6 months, a follow up MRI showed no change in size of her pituitary mass. Also, blood tests showed profound hypothyroidism, and after 6 month of thyroid replacement therapy, the patient was euthyroid. A repeated MRI of the brain showed complete resolution of the pituitary mass. Result: This case emphasizes the importance of evaluation of thyroid function in cases of elevated prolactin and gonadal dysfunction. Despite a lack of the typical clinical presentation of hypothyroidism, resolution of the patient’s symptoms and disappearance of her pituitary macroadenoma confirms the diagnosis. Conclusion: This case illustrates that primary hypothyroidism can present with amenorrhea and pituitary mass.

Keywords ● Amenorrhea ● Hyperprolactinemia ● Hypothyroidism ● Pituitary     macroadenoma ● Prolactin

Citation: Jokic, D. and Wang,X.: Primary hypothyroidism associated with
hyperprolactinemia and pituitary macroadenoma. Thyroid Science, 6(10):CR1-4, 2011.