Macroprolactinoma in an adolescent female with primary amenorrhoea

Abstract

Summary: Paediatric pituitary adenomas are rare in children and adolescents and differ from adults in both clinical presentation and management. We present the case of a 14-year-old female with primary amenorrhoea secondary to a macroprolactinoma, showing a modest radiological and biochemical response to dopamine agonist (DA) therapy. Despite a 10-month duration of increasing DA therapy, initial symptoms of primary amenorrhoea and hyperprolactinaemia persisted, with new symptoms of weight gain, lethargy and low mood. A transsphenoidal resection of the macroprolactinoma was successfully performed, followed by the initiation of additional hormonal therapy. This case explores the unique challenges of treating a macroprolactinoma refractory to medical management in adolescence.

Learning points: Management of macroprolactinomas in childhood and adolescence can bring unique challenges, including a delay in sexual development, often presenting with primary or secondary amenorrhoea in girls.DA therapy is typically the first-line therapy in treating macroprolactinomas; however, resistance in paediatric and adolescent patients is associated with tumour size and initial prolactin levels.Surgical resection should be considered as a second-line therapy for adolescents unable to tolerate high-dose DA therapy or have inadequate response to DA therapy.There are a range of potential surgical complications, including permanent or transient diabetes insipidus, meningitis, cerebrospinal fluid leakage and hypopituitarism.Timely management of macroprolactinomas is important for secondary sex characteristics, bone development and psychological well-being.

Keywords: adolescent; macroprolactinoma; pituitary.

Figure 1

(A, B) Initial formal visual field testing demonstrates bitemporal hemianopia. (C, D) Repeat formal visual field testing after 7 months of DA therapy showed a 90% resolution.

Figure 2

(A, B) Initial brain MRI demonstrates a pituitary mass of 28 × 18 × 15 mm, which superiorly displaces the optic chiasm with no extension to the cavernous sinuses (left – coronal T2, right – sagittal T1). White arrows indicate pituitary adenoma. (C, D) Preoperative brain MRI demonstrates a reduction in size of pituitary mass of 17 × 16 × 12 mm with no displacement of the optic chiasm (left – coronal T1, right – sagittal T1). White arrows indicate pituitary adenoma. (E, F) Post-operative brain MRI demonstrates debulking of the pituitary macroadenoma (left – coronal T2, right – sagittal T1). White arrows indicate pituitary adenoma resection.

Figure 3

Serum prolactin trend in months following initial presentation, according to cabergoline (CBG) dose changes and surgery; black circle: no change to CBG dosage, red circle: increased CBG dosage, green circle: decreased CBG dosage. The PRL levels on initial presentation were 26,286 mIU/L and steadily decreased to 4,930 mIU/L following commencement and titration of CBG dosages up to 3 mg weekly. Surgical intervention was performed at 11 months post-initial presentation. Initial post-operative PRL was 738 mIU/L, and CBG was ceased. By 16 months, PRL had steadily increased again to 3,142 mIU/L, resulting in a re-introduction of CBG and subsequent long-term use.

Figure 4

Histologic slides of pituitary biopsy. (A) Haematoxylin and eosin, (B) PRL expression, (C) SSTR2 expression and (D) SSTR5 expression.