Background: Pituitary prolactinoma containing spherical amyloid is rare. Squash smear findings of spherical amyloid in pituitary prolactinoma are characteristic.
Case: A 25-year-old woman presented with a pituitary tumor. The intraoperative squash smear showed abundant, homogeneous, eosinophilic material with multiple prominent striations. The scattered atypical cells in the periphery contained an irregular, bizarre nucleus; coarse chromatin; occasional prominent nucleoli; rare cytoplasm; and prolactin immunoreactivity.
Conclusion: The characteristic squash smear findings should be helpful in the diagnosis of this rare tumor.