[Clinical and functional characteristics of giant pituitary adenomas in the population of patients in the Moscow region].

Benign pituitary tumors are the most common sellar neoplasms. Lesions larger than 39 mm in the maximum dimension are called giant. They are rare, and, therefore, there are few data on the clinical and morphological features of giant pituitary tumors with different hormonal activity.
Aim: The aim of this study was to identify the clinical and functional features of giant pituitary tumors with different hormonal activity.
Material and Methods: We analyzed data of clinical, laboratory, and instrumental examinations of 351 patients diagnosed with pituitary macroadenomas at the Moscow Regional Research Clinical Institute in the period between 2008 and 2017: there were 144 hormonally inactive pituitary adenomas and 207 hormonally active pituitary adenomas (65 prolactinomas and 142 somatotropinomas).
Results and Discussion: Among 351 patients with pituitary macroadenomas, there were 32 (9.1%) giant adenoma cases: 18 (12.5%) 144 patients with hormonally inactive pituitary adenomas and 14 (6.8%) 207 patients with hormonally active pituitary adenomas 6 (3.9%) 65 prolactinomas and 6 (2.9%) 142 somatotropinomas. The volume of giant adenomas was somewhat larger among somatotropinomas 48 926 [35 067; 97 650] mm ³ and prolactinomas 36 872 [15 281; 75 102] mm ³ compared to that of hormonally inactive pituitary adenomas 26 933 [21 910; 42 895] mm ³ . Tumors had predominant suprasellar and posterosellar growth (31 (97.8%) and 29 (90.6%) cases, respectively). The most common first patient complaints were visual impairments (59.4%) and headache and/or dizziness (43.8%). Correspondingly, due to these complaints, 16 (50%) patients first consulted an ophthalmologist. Hypopituitarism detected before any treatment was present in 16 (50%) patients.
Conclusion: In most cases, visual impairments and headaches/dizziness were the first manifestations of giant pituitary adenomas; therefore, ophthalmologists and neurologists should always refer patients with these complaints to MRI. Patients with identified giant pituitary tumors should be referred to an endocrinologist for exclusion of hypopituitarism and, if necessary, timely prescription of hormonal therapy.