A giant prolactinoma with visual field loss: Rapid improvement with cabergoline in 5 years survey

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: MON 167-198-Hypothalamus-Pituitary Development & Biology
Monday, June 17, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board MON-171
Ertugrul Tasan*1, Hakan Hanimoglu2, Seda Yuce2, Muzaffer Ilhan1, Sevket Evran2 and Mehmet Yasar Kaynar2
1Bezmialem University, Istanbul, Turkey, 2Bezmialem University, Turkey
Introduction: Prolactinomas are  almost always benign with different amounts of prolactin-secreting pituitary tumors and an incidence of 40% and the vast majority of functional tumors.Giant prolactinomas are characterized by large size (>40mm in diameter), massive extrasellar involvement and usually asociated with high serum prolactin levels (>1000 ng/ml). They are a rare subset of macroadenomas.Limited studies demonstrated that cabergoline should be the effective as a first-line therapy and successfully used in giant prolactinomas.  The aim of this case report was to evaluate the efficacy of cabergoline treatment on rapid improvement in visual field defect, tumour shrinkage, prolactin level normalization in a patient  with giant prolactinoma.

 Clinical Case: 33 year-old man patient, he applied for occasional headaches and impairment of the sense of sight. Hormonal investigations showed hyperprolactinemia. Magnetic resonance imaginig of the pituitary gland showed a 54x40x40 mm pituitary adenoma with optic chiasmatic compression and left sphenoid sinus invasion. The tumor caused a loss of visual field of the right side. Cabergoline theraphy was started with dose of 1.5 mg/week. Fifteen days later, the clinical visual acuity examination showed that a significant improvement in the patient with visual field defect. 1 month later, clinical visual acuity examination showed improvement in the patient's visual field. After the five years follow-up magnetic resonance imagining showed reduction of the adenoma size (17x12 mm) was significant.

 Conclusion: Time to decrease in prolactin, tumoral shrinkage and improvement in visual field defect from the onset of treatment ranged from several weeks to more than years.In this case, the normalization of prolactin levels under treatment with cabergoline in 2 months, improvement in the visual field defect in 15 days and reduction in tumor size was observed in 1 month. The variation of response to cabergoline treatment reflects different degrees of sensitivity to cabergoline, perhaps related to the level of D2 dopamine receptor expression in the prolactin-secreting tumors or the ratio of the receptor isoforms. Our findings suggest that, in giant prolactinomas cabergoline can be used as a first-line therapy because tumoral shrinkage without a surgical procedure and rapid improvement in visual field defect is achieved with this medical treatment.

Nothing to Disclose: ET, HH, SY, MI, SE, MYK

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