Endocrine Abstracts

Introduction: Prolactinomas are rarely found in adolescents under 15 (incidence 0.1/1.000.000). They account for 50% of all types of pituitary adenomas in childhood and adolescence (2% of intracranial tumors). The mean time from onset of symptoms to diagnosis is 2.4 years on average for girls. In cases of macroadenomas, TSH and GH deficiency may coexist. The gold standard primary therapy is dopamine agonists. In case of non-response, or the presence of large prolactinomas with compressive effects mainly in the optic chiasm, surgical treatment is recommended.

Case presentation: A14^+2/12 year-old adolescent girl (weight: 67.6 kg, height: 1.57 m, BMI: 27.4 kg/m²), was referred for secondary amenorrhea. On physical examination, she was at Tanner stage 3–4 for both pubic hair and breast development. She had facial acne and reported occipital neuralgia. Initial laboratory results showed serum PRL at 705.4 ng/ml (normal: 4.79–23.3 ng/ml). MRI revealed a pituitary macroadenoma (16 × 13 × 15 mm) in the right pituitary lobe that encircled the right carotid artery in the cavernous sinus, while slightly pushing to the left the rest of the gland, without suprasellar projection. The visual fields examination was normal. The patient was initially started on cabergoline 0.5 mg twice weekly and gradually titrated up to 0.75 mg twice weekly, leading to menstrual cycle reappearance. Due to continuous presence of marginally high morning cortisol blood levels at 691.5 nmol/l (normal: 171–536 nmol/l), the HPA axis was assessed with overnight dexamethasone suppression test, low dose dexamethasone test and 24 h urine cortisol levels. The results were within normal limits. Fifteen months later, an MRI revealed that the macroadenoma had degenerated and significantly decreased in size (10 × 11 × 14 mm), while the remaining gland was no longer deviated to the left, nor was the internal carotid artery significantly encircled. Prolactin levels were at 43.1 ng/ml.

Conclusion: Prolactinomas are rarely found in adolescents under 15 years of age. For early diagnosis and treatment, it is very important to assess pituitary gland function in adolescent girls with menstrual disorders or amenorrhea, especially when combined with headache or vision disorders.