Pituitary pseudotumor. Mimicry of recurrent prolactinoma by a chronic intrasellar hematoma

In the increasing cohort of patients being observed after pituitary microneurosurgery for prolactin-secreting adenomas, tumor recurrence remains a concern. We describe a patient with a prolactinoma treated by transsphenoidal pituitary surgery who resumed cyclic menses for one year postoperatively before manifesting progressive headaches, intermittent diplopia, secondary amenorrhea, and anterior pituitary failure. Invasive and noninvasive neuroradiologic procedures suggested recurrent tumor with suprasellar extension. However, reoperation of the pituitary disclosed a chronic intrasellar hematoma expanding under increased pressure within the enclosed sellar space. We discuss a putative mechanism for the pathophysiology of this syndrome, and tentatively designate it "pituitary pseudotumor". Recognition of this entity is important not only because reoperation is required for accurate diagnosis, but also because treatment with radiotherapy or bromocriptine mesylate for presumptive tumor progression or recurrence would be ineffective.