Neurology & Neurosurgery - Juniper Publishers
Mini Review
A 59 year old man was referred by his neurologist with symptoms of twelve days of binocular, horizontal diplopia and decreased visual acuity. His medical history was notable for hypertension and hyperlipidemia, adequately controlled with medication. He was a former 1 pack per day smoker but had stopped smoking 20 years previously. He was recently hospitalized for work-up of his symptoms in a community affiliate hospital where a magnetic resonance angiogram of the head was performed, which was unremarkable. Visual acuity was 20/40 in the right eye and 20/30 in the left eye. In addition, he had a trace afferent pupillary defect of the right eye and 12 Prism Diopter (PD) esotropia and 10 PD hypertropia in primary gaze which increased to 20 PD esotropia and 20 PD hypertropia in right gaze. The remainder of the eye exam was normal. He was diagnosed with sixth nerve palsy versus skew deviation, advised to patch the eye for symptomatic relief, and return in 8 weeks.
The patient experienced decreasing vision of the right eye and developed right-sided headache and periorbital pain, prompting a follow-up visit two weeks later. His visual acuity had decreased to light perception, and his pupillary and motility exams remained unchanged. Dilated fundus exam was unremarkable. The differential diagnosis included ophthalmic artery occlusion, optic neuritis or giant cell arteritis, and he was admitted to the same community affiliate hospital and received high dose intravenous steroids. Computed tomography imaging revealed near complete opacification of the right sphenoid sinus and enhancement and thickening of the right optic nerve. On follow-up visit, his visual acuity in the right eye had improved to 20/400, but he still had an afferent pupillary defect and there was no improvement in ocular motility. He was then referred to a tertiary care hospital for dedicated Magnetic Resonance Imaging (MRI) of the brain and orbits and further evaluation and management. The MRI scan revealed a 3.6 x 2.2 x 2.8 cm enhancing sphenoid sinus mass, with extension through the right orbital apex and annulus of Zinn with 270 degrees of encasement and superior displacement of the right optic nerve (Figure 1). Subsequent sphenoid sinotomy and biopsy demonstrated diffuse large B-cell lymphoma with high proliferation index (Figure 2). The patient was referred to neuro-oncology for chemotherapy.
Diffuse large B cell lymphoma is the most common subtype of non-Hodgkin’s lymphoma but rarely arises from the paranasal sinuses [1,2]. The sphenoid sinus as site of origin is especially rare, with only 19 reports in English literature; incidence is slightly more common in Asian patients [1]. Yoshihara et al. reviewed 15 reports and found 13/15 (86.7%) presented initially with ptosis or diplopia caused by CN III, IV, or VI palsy [1]. This is the fourth report in the English literature to describe sphenoid lymphoma with orbital apex syndrome and optic neuropathy. Imaging findings that can be demonstrated with sphenoid lymphoma include permeative bone destruction, hemorrhage, or fibrous dysplasia [2]. As seen in our patient, lack of classical radiologic findings can lead to delay in diagnosis. Vision loss, diplopia affecting multiple cranial nerves, and an indolent course should alert clinicians to suspecting this entity. Prompt consultation with otolaryngology and medical oncology can afford the patient the greatest chance at preventing additional morbidity and mortality.
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