SAT-450 A Comparison of Clinical Features between Pituitary Incidentalomas and Pituitary Symptomatic Tumors

Objective: Pituitary tumors are discovered by imaging studies incidentally (incidentalomas), or based on certain clinical symptoms (symptomatic pituitary tumor). In this study, we investigated differences in clinical features between incidentalomas and symptomatic pituitary tumors. Patient and method: 151 patients who regarded as non-functioning pituitary tumor and underwent transsphenoidal surgery (TSS) between 2011 and 2017 at our institution were studied. Among 151 patients, pituitary tumors were discovered as incidentalomas in 83 (M/F; 45/38) and symptomatic in 68 (M/F; 39/29). Age, sex, BMI, reasons for taking imaging study, tumor maximum diameter, pituitary function and final pathological diagnosis were analyzed and compared between the two groups. Results: Patients with incidentalomas were older than those with symptomatic tumors (59.7±3.0 vs 54.8±3.3 y.o., p=0.03), though gender ratio and BMI did not differ between the two groups. Reasons for taking imaging studies were mainly because of headache that was not considered as a symptom of pituitary mass (n=29), medical checkup (n=17), dizziness (n=15) and trauma (n=8) in incidentalomas, whereas visual disturbance (n=46), acute headache due to pituitary apoplexy (n=9), hyponatremia (n=4) and irregular menstruation (n=2) in symptomatic tumors. The size of incidentalomas were significantly smaller than those of symptomatic tumors (22.8±1.9 vs 27.1±2.0 mm, p=0.003). The incidence of pre-surgical pituitary hormone deficiency in both groups (incidentalomas vs symptomatic tumors) were 37.0% vs 66.1% for GH deficiency (P=0.007), 19.3% vs 39.7% for hypogonadism (P=0.007), 4.8% vs 16.2% for ACTH deficiency (P=0.027) and 7.2% vs 10.3% for TSH deficiency (P=0.57). Post-surgical hypopituitarism was observed more in symptomatic tumors (40.9% vs 70.6%, P=0.003). Pre-surgical diagnosis was either non-functioning adenomas (n=145) or Rathke’s cyst (n=6) in all patients, however after TSS, 3 patients in symptomatic group and one in each group were diagnosed as prolactinoma and pituicytoma, respectively. Conclusion: Incidentalomas were most frequently noticed by imaging for check on headache, whereas symptomatic tumors were by visual disturbance. Compared with incidentalomas, symptomatic tumors were larger, more associated with hypopituitarism that persisted still after TSS. These data suggested that detection of incidentalomas and their appropriate management might contribute better therapeutic outcomes of pituitary adenoma.