Endocrine Abstracts

Introduction: There are multiple causes of delayed puberty including constitutional delay in growth and puberty, chronic diseases, hypothyroidism, and pituitary tumours (e.g. craniopharyngioma). Delayed puberty due to macroprolactinoma is rare.

Case Presentation: A 23-year-old male was reviewed in the Endocrine clinic after presenting with headaches and generally feeling unwell. Blood test showed a high prolactin level of 84637, low FT 7.7, low testosterone level 0.1 with low LH 1.5 and FSH 0.5. IGF-1 was 58. MRI pituitary showed Pituitary Macroadenoma (3.0×2.7×2.2 cm). X-ray of left wrist revealed bone age of 14-15 years old. During his clinic review, he was found to have a high-pitched voice, pre-pubertal hair, pubic hair distribution Tanner stage 2, and micropenis. He was started on cabergoline 250 micrograms twice a week and his prolactin level improved to 15325 after 1 month of therapy then later to 1975. The cabergoline dose was increased/escalated to 500 micrograms twice a week

Discussion: Delayed puberty is diagnosed when there is a lack of secondary sexual characteristics at the age of 14 years in boys and the age of 13 years in girls. Some of the causes of delayed puberty include constitutional delay of growth and puberty, poor nutrition, hypothyroidism, and chronic diseases. The above causes are for patients with intact Hypothalamic-pituitary axis. The causes of delayed puberty may also be due to impaired hypothalamic-pituitary axis. These include tumours such as craniopharyngioma, astrocytoma, and impaired development of hypothalamic-pituitary axis in septo-optic dysplasia. Irradiation, trauma, or surgery to the hypothalamic-pituitary region may contribute to delayed puberty as well. This case demonstrated that the patient most likely developed the pituitary macroprolactinoma before puberty and it has been slow growing. Medical therapy with dopamine agonist has produced improvement in prolactin levels but the patient will need small dose of testosterone 50mg once a month to induce puberty.

Conclusion: Here we present a rare cause of delayed puberty caused by macroprolactinoma. Medical management is first line treatment with dopamine agonist such as cabergoline. It is also important in these cases to consider hereditary macroprolactinomas causes such as multiple endocrine neoplasia type 1 (MEN 1) and Familial isolated pituitary adenoma (FIPA) syndrome especially if two or more cases of pituitary adenomas appear in the same family in the absence of MEN 1 and Carney complex.