Endocrine Abstracts

Pituitary adenomas (PAs) account for 15-20% of intracranial tumors. PA with a cystic component are characterized in the MRI by a sellar, symmetrical, round or ovoid mass that enhances on T1- or T2-weighted images but does not concentrate gadolinium. We present the case of a 48-year-old man who in a headache study by Neurology requested a CT scan showing a cystic pituitary macroadenoma of 1.25cm confirmed by pituitary MRI. In the initial analysis, the pituitary function was preserved, but in the follow-up he was diagnosed with central hypothyroidism and hypogonadotrophic hypogonadism, so replacement treatment was started. In addition, a visual field study was performed, being normal. As it was a clinically non-functioning asymptomatic pituitary adenoma, we opted for conservative follow-up without surgery. During the follow-up of the patient, a control pituitary MRI requested three years later revealed a significant decrease in the size of the pituitary lesion with cystic semiology, with dimensions of 8x3mm. This decrease in size was confirmed in subsequent imaging tests, although the hormone deficits presented by the patient persisted. Nonfunctioning PAs can go unnoticed for years, and be diagnosed incidentally or when they grow and produce compressive symptoms (headaches, visual impairment) or hormonal deficiencies. In patients with asymptomatic, clinically nonfunctioning pituitary incidentalomas it is recommend conservative follow-up without surgery, with periodics MRI. Macroadenomas have a propensity to grow, but it has been seen that a small percentage (approximately 10%) may undergo spontaneous volume regression, perhaps due to silent ischemia, so continuous follow-up with repeated imaging is justified. Periodic reassessment of pituitary function is recommended in patients with macroincidentalomas because they are at risk of developing hypopituitarism. Medical therapy of pituitary incidentalomas has not been systematically studied. The reported efficacy of do pamine agonist, somatostatin analogues, and GnRH analogues varies widely. In the present case, there was a significant decrease in the size of the PA during follow-up without surgical or medical treatment, hence the importance of periodic radiological follow-up. In some cases, when tumor size regression occurs, pituitary function can be restored, a fact that did not occur in our case, so we will continue with clinical, radiological and biochemical follow-up of the patient.