Gonadotropin-releasing hormone-induced partial empty sella clinically mimicking pituitary apoplexy in a woman with a suspected non-secreting macroadenoma

Pituitary apoplexy has been reported as a rare complication of dynamic test ing used for the study of pituitary functional reserve. In 1993, a diagnosi s of non-secreting macroadenoma with moderate functional hyperprolactinaemi a was made in a 43-year-old woman. Soon after the start of therapy with bro mocriptine up to 5 mg/die, the patient complained of nausea and postural hy potension. As the symptoms persisted even when the dose was reduced to 2.5 mg/die, the patient was transferred to therapy with quinagolide at the dosa ge of 37.5 mu g/die. PRL levels quickly normalized (range 1.4-5.7 ng/ml) as well as menstrual cycles, and no side-effect was reported. In 1995 a sella r magnetic resonance imaging (MRI) showed no shrinkage of the known macroad enoma. In 1996, few hours after a gonadotropin-releasing-hormone (GnRH) tes t, which showed normal LH and FSH response and with baseline PRL levels in the normal range, the patient started complaining of severe frontal headach e, nausea and vomiting. No gross visual defects were present. An emergency computed tomography (CT) showed no evident hemorrhagic infarction in the ma croadenoma. The symptoms completely resolved in few days with steroidal and antiemetic therapy. A new MRI performed in 1998 showed a partial empty sel la and PRL levels were in the normal range under dopaminergic treatment. Th e pituitary functional reserve proved normal on dynamic testing. The tempor al association between the onset of symptoms and the GnRH test strongly sug gests an association between the two events. No evident signs of pituitary apoplexy (either on emergency CT or hormonal evaluation) were detected. The authors suggest that GnRH can cause severe side-effects that mimic pituita ry apoplexy without related morphological evidence and that, in our particu lar case, it can have caused the gradual disappearance of the non-secreting macroadenoma. Moreover, a causal role of the chronic dopaminergic treatmen t cannot be completely ruled out. (J. Endocrinol. Invest. 23: 118-121, 2000 ) (C)2000, Editrice Kurtis.