Endocrine Abstracts

There are some data concerning high prevalence of infrasellar extension of somatotropinomas. To reveal any differences expansion of pitutary macroadenomas with various hormonal secretion, we have analyzed MRI data of 175 pituitary macroadenomas: 87 non-functioning adenomas (NFAs), 48 prolactinomas, 43 somatotropinomas. The sizes of pituitary tumour (vertical, sagittal, frontal): NFAs 24 (17.5; 34.5)mm, 23 (17.4; 28) mm, 23 (18; 30) mm; prolactinomas 21 (15; 31) mm, 20 (16; 30) mm, 20 (14; 30) mm; somatotropinomas – 18 (14; 25) mm, 18.2 (14; 24) mm, ? 17 (14.5; 23) mm. The tumour volume varied: in NFAs from 618 to 68753 mm³ (median 6620 (2638; 14492) mm³), in prolactinomas 565–86871 mm3 (median 5365 (1495; 10316) mm³), in somatotropinomas 352–124501 mm³ (median 3052 (1696; 5727) mm³) (P<0.001). Prevalence of suprasellar, infrasellar and laterosellar extensions were: NFAs–94, 62, and 39%; prolactinomas – 75, 64 and 62%; somatotropinomas – 61, 75, and 44%, respectively. Suprasellar tumour growth was predominant in NFAs and prolactinomas but not in somatotropinomas (P<0.001). Higher frequency of infrasellar growth of somatotropinomas was noted but the difference was not significant in comparison with other tumours (P>0.05). Obvious prevalent incidence of laterosellar growth of prolactinomas was observed compared with both NFAs (P=0.002) and somatotropinomas (P<0.016). Optic chiasm compression according to MRI data was found in 55% of NFAs, 35% of prolactinomas and 19% of somatotropinomas (P<0.001) and it was correlated with suprasellar growth and vertical size >18 mm. Thus, in our cohort of patients non-functioning pituitary adenomas have markedly larger volume with predominant suprasellar growth and high frequency of chiasm compression compared with hormonally active pituitary tumours. Prolactinomas and somatotropinomas did not differ in volume, however, had some differences in growth directions: this is the first data concerning high prevalence of laterosellar extension of prolactinomas, predominant infrasellar growth of somatotropinomas was also observed without significant difference in comparison with other pituitary tumours.