Endocrine Abstracts

Introduction: Pituitary tumorous hyperplasia with hyperprolactinemia has been described as a rare presentation of primary hypothyroidism. The loss of thyroxin feedback inhibition in primary hypothyroidism causes overproduction of thyrotropin-releasing-hormone (TRH), which results in secondary pituitary enlargement. TRH has a weak stimulatory effect on the lactotroph cells of the pituitary, so a mild to moderate increase in prolactin (PRL) levels is expected. This report descri...