Giant prolactinomas: clinical manifestations and outcomes of 16 Arab cases

The management of giant prolactinomas remains a major challenge, despite dopamine agonists being the first line of treatment, owing to its efficacy to normalize prolactin levels and reduce tumor volume. The aim of this study is to characterize the therapeutic aspects, manifestations and outcomes of 16 cases of giant prolactinomas admitted at a single tertiary center in Riyadh, Saudi Arabia.

Retrospective data collection involving 16 Saudi patients diagnosed with giant prolactinoma at the Pituitary Clinic in King Fahad Medical City, Riyadh, Saudi Arabia between January 2006 and July 2012.

A total of 16 patients (ten males; six females) with age of diagnosis between 21 and 55 years (mean 34.9 years) were included in the analysis. The most common presenting features include headache, visual defects and sexual dysfunction. Baseline mean serum prolactin level were extremely high for both sexes which eventually decreased by as much as 97% after cabergoline treatment. Serum prolactin concentrations completely normalized in six patients and significantly decreased in five patients 3-5 times that of normal range. Tumor volume also decreased by an average of 86% for males and 87% for females. Two patients had no tumor size change with cabergoline and required surgery.

Findings indicate that cabergoline provides dramatic clinical improvements with excellent safety profile. Cabergoline should therefore be considered as the primary therapy for giant prolactinomas.