Vanishing Pituitary Macroadenoma: A Case Report.

Pituitary macroadenomas are the most common suprasellar lesions in adults and are typically managed surgically through transsphenoidal resection when symptomatic. Due to their close proximity to the optic chiasm, pituitary macroadenomas often present with signs of bitemporal hemianopsia. Alternatively, these tumors can cause mass effect, thus presenting with signs of elevated intracranial pressure or can present with signs and symptoms of endocrine dysfunction. Here, we discuss a 55-year-old male diagnosed with a non-functioning pituitary macroadenoma (NFPA) based on cranial imaging, ophthalmologic exam, and endocrine evaluation. Following diagnosis, the patient was scheduled for transsphenoidal hypophysectomy. On magnetic resonance imaging (MRI) done three and half months later for surgical planning, the tumor had almost completely regressed and only residual pituitary tissue was noted. We describe the presentation and clinical course of the patient, summarize chief differential diagnoses, and discuss potential managements of these conditions.