Gender differences in macroprolactinomas: a single centre experience

Macroprolactinomas are the most common functional pituitary tumours. Hypotheses proposed to explain predominance of large tumours in males are: i) diagnostic delay, as hyperprolactinaemia remains under recognised in males and ii) gender-specific difference in tumour proliferation indices. Our study objectives are to compare gender differences in clinical, biochemical, radiological features, management outcomes and cabergoline responsiveness in macroprolactinomas. Drug resistance was defined as failure to achieve prolactin normalisation and O50% reduction in tumour volume with cabergoline (3.5 mg/week dose for minimum 6 months duration). The baseline characteristics of 100 patients (56 females and 44 males) with macroprolactinoma were analysed. Drug responsiveness was analysed in 88 treatment naive patients, excluding 12 post-primary trans-sphenoidal surgery cases. We found that females (30.29G10.39 years) presented at younger mean age than males (35.23G9.91 years) (P!0.01). The most common presenting symptom was hypogonadism (oligo-amenorrhoea/infertility) in females (96.15%) and symptoms of mass effect (headache and visual field defects) in males (93.18%). Baseline mean prolactin levels were significantly lower in females (3094.36G6863.01 ng/ml) than males (7927.07G16 748.1 ng/ml) (P!0.001). Maximal tumour dimension in females (2.49G1.48 cm) was smaller than males (3.93G1.53 cm) (P!0.001). In 88 treatment