Endocrine Abstracts

Objective: Abscesses in pituitary adenomas are rare. Continuous progression and haematogenous spread of infections are considered the main pathogenic mechanisms. A standard therapeutic regimen does not exist.

Methods: We report on the case of a 56-year-old male who had been treated with cabergoline for a macroprolactinoma for 4.5 years. The patient presented to our emergency room with sudden deterioration of visual acuity and right oculomotor paresis. A pituitary abscess was identified in MRI, urgently evacuated transsphenoidally and then treated with i.v. antibiotics. We provide clinical, histopathological and MRI findings as well as a follow-up at 21 months after surgery. We compare our case to other cases from the literature and, considering the evidence in rodents, discuss potential pathogenic mechanisms with special regard to immunodeficiency.

Results: The favourable result we observed so far as well as the cases reported in the literature warrant to consider urgent transsphenoidal evacuation followed by i.v. administration of antibiotics as treatment option of choice in pituitary abscesses. Immunodeficiency due to the mass effect of a macroprolactinoma with subsequent suppression of GH secretion and decreased IGF1 release or due to suppression of prolactin-triggered immunomodulation as a side effect of treatment with dopamine agonists have to be taken into consideration as potentially pathogenic mechanisms.

Conclusions: Although pituitary abscesses are rare, neurosurgeons, endocrinologists and ophthalmologists should be aware of this life-threatening entity. Regular follow-up MRI scans in patients treated with dopamine agonists for a prolactinoma are warranted to timely detect signs of potential inflammation. Urgent transsphenoidal evacuation followed by i.v. administration of antibiotics should be considered as treatment option of choice in pituitary abscesses. The function of the immune system in patients with prolactinoma and treated with dopamine agonists should be a matter of further investigations.