Pituitary_Macroadenoma_Presenting_With_Monocular_Temporal_Hemianopia

Trainees’ Corner Section Editors: Vivek R. Patel, MD Prem Subramanian, MD, PhD Pituitary Macroadenoma Presenting With Monocular Temporal Hemianopia Ankur Gupta, MA, FRCOphth, Mira Deshmukh, BSc, MBBS, George Palexas, MBBCh, MMed Abstract: A 35-year-old primigravida woman presented to the eye emergency department with reduced visual acuity in the right eye. Humphrey visual field testing showed a monocular right eye temporal hemianopia before delivery. An MRI after delivery revealed a largely symmetrical pituitary macroadenoma with chiasmal compression. This is a rare presentation of a pituitary macroadenoma especially when the tumor is largely symmetrical. Journal of Neuro-Ophthalmology 2021;41:e267–268 doi: 10.1097/WNO.0000000000001119 © 2020 by North American Neuro-Ophthalmology Society VA in the right eye was 20/40, and VA in the left eye was 20/20. The rest of the ocular examination was within normal limits. One week later, she had a 24-2 Humphrey visual field which showed a right eye temporal monocular hemianopia (Fig. 1). Two weeks later, VA in the right eye had reduced to 20/200, with no change in the left VA, and a right afferent pupillary defect was present. She gave birth 2 days afterward and returned for review 2 weeks after giving birth with a VA of 20/30 in the right eye. An A 35-year-old primigravida woman presented to the eye emergency department with reduced visual acuity (VA) in the right eye. She was 37 weeks pregnant at presentation. FIG. 1. Humphrey visual field testing (24-2 HVF) before delivery showing a right eye temporal monocular hemianopia. Ophthalmology Department, North Middlesex Hospital NHS Trust, London, United Kingdom. The authors report no conflicts of interest. Address correspondence to Ankur Gupta, MA, FRCOphth, North Middlesex Hospital, Stirling Way, London, United Kingdom N18 1QX; E-mail: [e-mail] Gupta et al: J Neuro-Ophthalmol 2021; 41: e267-e268 FIG. 2. Coronal T2-weighted MRI acquired after delivery. The white arrow points to a pituitary macroadenoma of approximately 20 mm in craniocaudal length compressing the optic chiasm and splaying the intracranial segments of the optic nerves. e267 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Trainees’ Corner FIG. 3. Humphrey visual field testing (24-2 HVF) after delivery showing a right eye rim artifact and persistent mild temporal defect, denser superiorly. The left eye field is largely normal. MRI conducted a few days later revealed a largely symmetrical pituitary macroadenoma with chiasmal compression (Fig. 2). Serum investigation revealed only an elevated prolactin level of 718 ng/mL. It is well described that such lesions enlarge during pregnancy; however, imaging was not obtained before delivery (1). This would have accounted for her gradually reducing vision which recovered after giving birth. Visual fields taken after delivery (Fig. 3) show a right eye rim artifact and persistent mild temporal defect, denser superiorly. The left eye field is still largely normal after delivery. e268 Others have described that a monocular temporal hemianopia may be explained by involvement of the ipsilateral optic nerve close enough to the chiasm to selectively impair conduction in ipsilateral crossing fibers but too anterior to affect the crossing nasal retinal fibers from the contralateral eye (2,3). Such a field defect is unusual and not very common in pituitary adenomas. This is especially true when, as in our case, radiologically, the tumor appears symmetrical. It is unclear why such a field defect should be present in a largely symmetrical tumor. It has been suggested that this could be due to differential occlusion or stasis of chiasmal nutrient blood vessels (2,4–6). It is worth considering pituitary lesions in patients presenting even with monocular field defects. We show there may not be a link with the field defect and the laterality of the lesion; however, no imaging was obtained before delivery; thus, it is possible that there was asymmetric enlargement of the tumor at this stage. REFERENCES 1. Imran SA, Ur E, Clarke DB. Managing prolactin-secreting adenomas during pregnancy. Can Fam Physician. 2007;53:653–658. 2. Hershenfeld SA, Sharpe JA. Monocular temporal hemianopia. Br J Ophthalmol. 1993;77:424–427. 3. Brooks DB, Subramanian PS. Monocular temporal hemianopia with septo-optic dysplasia. J Neuroophthalmol. 2006;26:195–196. 4. Hoyt WF. Correlative functional anatomy of the optic chiasm. Clin Neurosurg. 1970;17:189–207. 5. Schneider RC, Kriss FC, Falls HF. Pre-chiasmal infarction associated with intrachiasmal and suprasellar tumors. J Neurosurg. 1970;32:197–208. 6. Bergland RM, Ray BS. The arterial supply of the human chiasm. Neurosurg. 1969;31:327. Gupta et al: J Neuro-Ophthalmol 2021; 41: e267-e268 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited.