NCOG-32. PROGNOSTIC IMPLICATIONS OF SIZE OF PITUITARY MACROADENOMAS: A COMPARATIVE ANALYSIS OF GIANT ADENOMAS WITH NON-GIANT MACROADENOMAS

Abstract

Abstract BACKGROUND In this study we compared giant pituitary adenomas (GPAs) and non-giant pituitary macroadenomas (nGPAs) on the basis of presenting complaints, surgical procedures, tumor resections and outcomes. METHODS A retrospective analysis (2006-2017) of pituitary macroadenomas was performed where tumors were divided into two groups; tumors greater than 4 cm were classified as GPAs while macroadenomas smaller than 4 cm were termed as nGPAs. Both GPA and nGPA had 75 patients in each group. RESULTS The most common complaint of all patients was visual deterioration (77.3% of patients with nGPAs and 89.3% of patients with GPAs). Visual field defects were present in 55 patients (73.3%) in the nGPA group compared to 68 patients (90.7%) in the GPA group (p=0.006). The mean volume of nGPAs was 6.3 cm3 (range 0.45 cm3 to 22 cm3 while the mean volume of GPAs was 30.1 cm3 (range 10.8 cm3 to149.4 cm3) (p=0.001). The mean extent of resection was 88.9% for nGPAs whereas the mean extent of resection was 76.7% for GPAs (p=0.03). Craniotomy was required only in the GPA group (5 patients, 6.7%) (p=0.023). Tumor recurrence/progression was seen in 9.3% of patients with nGPAs and 44% of patients with GPAs (p=< 0.001). Re-do surgery was required in 2.7% of nGPA cases (via transsphenoidal approach) and 32% of GPA cases; in this GPA subgroup, 22.7% patients required transsphenoidal surgeries while 9.3% patients required transcranial surgeries. Stereotactic radiosurgery in recurrence/progression accounted for 4% of nGPA patients and 22.7% of GPA patients. There were 3 mortalities, all in GPA group. Overall, nGPA group had better postoperative course as compared to GPA group. CONCLUSION The frequency of preoperative symptoms in GPAs is more significant and associated with lesser chances of gross total tumor resection, higher rates of recurrence, and worse postoperative course in comparison to nGPAs.