Expect the Unexpected, When at a Diagnostic Crossroad!

A 44-year old man presents with subacute onset vision loss in the right more so than the left eye for several months before seeking medical attention. His vision at initial presentation was CF OD and 20/40 OS. He had a right RAPD. Fundus examination showed marked optic atrophy with no recordable color vision in either eye. His baseline MRI scan showed some mild chiasmal thickening and enhancement of the right more than left optic nerves.

Poster 190 Expect the Unexpected, When at a Diagnostic Crossroad! Etienne Benard-Seguin1, Michael Mak1, Suzanne Kosteniuk1, Yves Starrreveld1, Ronald Kapadia1, Muhammad Faruqi1, Kristopher Langdon1, Fiona Costello1 1 University of Calgary, Calgary, Canada Introduction: A 44-year old man presents with subacute onset vision loss in the right moreso than the left eye for several months before seeking medical attention. His vision at initial presentation was CF OD and 20/40 OS. He had a right RAPD. Fundus examination showed marked optic atrophy with no recordable color vision in either eye. His baseline MRI scan showed some mild chiasmal thickening and enhancement of the right more than left optic nerves. Description of Case(s): An extensive evaluation was undertaken to exclude infiltrative, genetic and inflammatory causes of vision loss including whole neural axis MRI, LHON mutation testing, anti-MOG and anti-NMOSD antibodies, connective tissue evaluation, HIV testing, syphilis serology, toxic screen, PET CT imaging, and bronchoscopy to test for sarcoidosis. The patient demonstrated initial improvement with high dose corticosteroid therapy, yet his vision deteriorated to NLP OD and 20/60 OD with a junctional scotoma pattern of visual field loss. Repeat MRI scan of the brain and orbits revealed a cystic mass involving the optic chiasm and right optic nerve. Pathology revealed a features consistent with a germinoma and is currently undergoing radiation. Scrotal ultrasound was unremarkable. Conclusions, including unique features of the case(s): Intracranial germ cell tumors are very rare and represent less than 1% of intracranial tumors in the United States. The majority of intracranial germ cell tumors localize to the suprasellar space (30%–40%), pineal region (48%–60%), or both (6%–10%). A review of the literature performed by Dr. Cohen et al found only 6 case reports of primary, nonexophytic anterior visual pathway germ cell tumors. All reported cases have been in male patients with a mean age of 21 years at time of diagnosis. All reported cases presented with painless, progressive vision loss with endocrine abnormalities such as Diabetes Insipidus. Our case is particular as, to our knowledge, it is the oldest reported case in the literature. References: Cohen D, Bhatti T, Giannini C, Eckel L, Garrity J, Chen J, Intracranial Pure Germinoma With Optic Nerve Infiltration, Journal of Neuro-Ophthalmology: March 2020 - Volume 40 - Issue 1 - p 112-116 Bowman CB, Farris BK. Primary chiasmal germinoma: a case report and review of the literature. J Clin Neuroophthalmol. 1990;10:9–17. DiLuna ML, Two AM, Levy GH, Patel T, Huttner AJ, Duncan CC, Piepmeier JM. Primary, non-exophytic, optic nerve germ cell tumors. J Neurooncol. 2009;95:437–443. Horowitz MB, Hall WA. Central nervous system germinomas: a review. JAMA Neurol. 1991;48:652–657. Matsutani M. Chapter 42— germ cell tumors. In: Berger MS, Prados MD, eds. Textbook of Neuro-Oncology. Philadelphia, PA: W.B. Saunders, 2005:310–320. Wilson JT, Wald SL, Aitken PA, Mastromateo J, Vieco PT. Primary diffuse chiasmatic germinomas: differentiation from optic chiasm gliomas. Pediatr Neurosurg. 1995;23:1 5; discussion 6. Keywords: orbit/ocular pathology, tumors Financial Disclosures: The authors had no disclosures. Grant Support: None. Contact Information: None provided. 190 | North American Neuro-Ophthalmology Society