Endocrine Abstracts

Background: Incidental macroprolactinoma is an unsuspected prolactin-secreting pituitary adenoma larger than 1 cm that is discovered by an imaging test performed for an unrelated reason.

Case presentation: A 25-year-old man was diagnosed with incidental macroprolactinoma (30.3×23.4×22.6 mm) following a head MRI scan after trauma. At the initial investigation, the patient had no complaints and denied any sexual dysfunction. Physical examination showed obesity without hypertension, reduced face and normal body hairiness, abdominal stretch marks and vitiligo of genitalia. No other pathology of the genitalia nor gynecomastia were found. Hormone testing revealed high prolactin (PRL) (36768,6 mU/l), DHEA-SO4 (23 umol/l) and aldosterone (1088 pmol/l) levels while FSH (0.83 U/l), LH (0.82 U/l), testosterone (T) (3.56 nmol/l) and IGF-I (7.92 nmol/l) were low. Despite low T, the spermogram was normal. Neuro-ophthalmic examination showed no pathology. The patient refused surgery and was successfully treated with low doses of Bromocriptine. After 5 months of treatment, macroadenoma shrank by 45% and serum PRL decreased to normal. However, LH, FSH and T levels remained low. Abdominal MRI scan excluded adrenal mass suggesting functional hyperdehydroepiandrosteronism. Following the limitations of movement and healthcare access during the SARS CoV 2 pandemic, the patient stopped his visits to the endocrinologist. Moreover, thinking of the lack of symptoms as the “disappearance of the disease”, he also stopped Bromocriptine intake. 4 months after drug withdrawal, a head MRI scan revealed the increase of the tumour by 50% comparing to the latest scan. After the renewal of medication intake PRL quickly decreased to normal.

Conclusions: Most prolactinomas are easily treated by medications or surgery. However, the absence of symptoms does not necessarily indicate a benign course of the disease and continued monitoring of lesion size, as well as hormonal status, is necessary.