title: Seesaw nystagmus caused by giant pituitary adenoma: case report.
abstract: Giant pituitary adenomas are uncommonly large tumors, greater than 4 cm in size that can produces endocrine symptoms, visual loss and cranial nerve palsies. We report the rare occurrence of seesaw nystagmus as the presenting sign of giant pituitary adenoma. A 50-year-old man presented with headache associated with visual loss and seesaw nystagmus. Perimetry revealed bitemporal hemianopia and magnetic resonance imaging showed a giant pituitary adenoma. After surgery, nystagmus disappeared. Our case is relevant in understanding its pathogenesis since it documents seesaw nystagmus in a patient bitemporal hemianopia due to a large tumor but without mesencephalic compression.
authors.affiliation: Division of Ophthalmology, Hospital das Clínicas, University of São Paulo Medical School, São Paulo, SP, Brazil. fredcastelo@terra.com.br
authors.forename: Frederico Castelo
authors.initials: FC
authors.lastname: Moura
authors.forename: Allan Christian Pieroni
authors.initials: AC
authors.lastname: Gonçalves
authors.forename: Mário Luiz Ribeiro
authors.initials: ML
authors.lastname: Monteiro
mesh_terms: D000236:Adenoma / Q000150:complications* / Q000601:surgery; D006423:Hemianopsia / Q000175:diagnosis / Q000209:etiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009759:Nystagmus, Pathologic / Q000175:diagnosis / Q000209:etiology*; D010911:Pituitary Neoplasms / Q000150:complications* / Q000601:surgery; D058609:Visual Field Tests