Prolactin-producing pituitary adenoma with abundant spherical amyloid deposition masquerading as extensive calcification

A 53-year-old male presented with a case of prolactin-producing pituitary adenoma with abundant spherical amyloid depositions masquerading as extensive calcification and manifesting as visual disturbance. Computed tomography revealed a large high density mass suggesting calcified tumor in the intra- and supra-sellar regions. Magnetic resonance imaging revealed a heterogeneously enhanced large pituitary tumor reaching lateral ventricle. Blood prolactin level was elevated to 5971 ng/ml. Cabergoline treatment for 3 months provided considerable shrinkage of the tumor but failed to improve the visual symptoms. Transcranial surgery revealed that the tumor was fibrous and included abundant grayish translucent spherical granules with diameter of 0.5-1.5 mm. Immunohistochemically, the tumor was strongly positive for prolactin. Congo red stain and polarized light showed that these spherical bodies were amyloid depositions. No calcification was noted.