Outcomes of pituitary apoplexy: a comparison of microadenomas and macroadenomas

Purpose: We aimed to assess clinical characteristics of apoplexy of pituitary microadenomas compared to macroadenomas. Methods: We retrieved clinical records of patients > 18 years old, hospitalized in Rambam hospital between January 2001 and October 2017, with pituitary apoplexy and follow-up of at least one year. We compared clinical course and outcomes of apoplexy between patients with microadenomas and macroadenomas, and between patients who received conservative or surgical treatment. Statistical analysis was done using Fisher’s exact and Mann–Whitney tests. Results: Twenty-seven patients with pituitary apoplexy were included in the final analysis: mean age was 40.7 ± 12.5 years, 13(48%) were female, 7(26%) had microadenomas, and 21(78%) harbored clinically nonfunctioning pituitary adenomas. Upon admission, hyponatremia, random cortisol level of < 200 nmol/L, and secondary hypothyroidism, were evident in 6/20, 8/18, and 4/18 patients with macroadenoma and 1/5, 2/5, and 1/6 patients with microadenoma, respectively (P = 1.0). Hypogonadotropic hypogonadism was evident in 9/12 men with macroadenoma. In 12 macroadenoma patients, the tumor abutted the optic chiasm, of whom eight had visual field defects. Fifteen patients with macroadenoma and two with microadenoma underwent transsphenoidal surgery. Median follow-up was 3 years. At last follow-up visit, patients with microadenoma had lower rates of corticotropic deficiency or secondary hypothyroidism compared to macroadenoma patients (1/7 vs. 13/20 respectively, p = 0.033). Only two patients with macroadenomas had persistent visual field defects. Outcomes were comparable between conservative and surgical treatment groups. Conclusions: Long term pituitary hormone deficiencies are more common in pituitary apoplexy patients with macroadenomas. Apoplexy of pituitary microadenoma carries a more favorable prognosis.