HIV-Associated Rapidly Progressive Lymphoma of the Cavernous Sinus

A 49-year-old man with newly diagnosed but well- controlled HIV on HAART (CD4+ 254, viral load undetectable) presented to the emergency department (ED) with 3 days of right-sided headache, orbital pressure, and acute-onset horizontal binocular diplopia that was worse at distance. Initial examination revealed only an isolated right eye abduction deficit. Laboratory results were notable for elevated inflammatory markers (ESR 82 and CRP 16) and positive serum oligoclonal bands. MRI brain and orbits revealed a T2 hypointense, mildly enhancing, diffusion-restricting lesion in the right cavernous sinus abutting the internal carotid artery (ICA) (Fig. 1A, B). Computed tomography (CT) chest, abdomen, and pelvis revealed a nonspecific right lower lobe nodule. Lumbar puncture with flow cytometry and cytology was unrevealing. The patient received high-dose intravenous steroids, given concern for an inflammatory process without change of symptoms. On rereview of imaging, there was concern for cavernous sinus thrombosis, so therapeutic anticoagulation was also initiated. He was discharged on anticoagulation alone. Two weeks later in neuro-ophthalmology clinic, he noted a change in his binocular horizontal diplopia—now present in all directions of gaze. Examination showed mild right ptosis, 80% adduction, 70% supraduction, 70% abduction, and 40% infraduction of the right eye, and full ocular ductions of the left eye consistent with a new pupilsparing right CN III palsy. Repeat MRI brain and orbits showed interval enlargement of the right cavernous sinus lesion in addition to new skull-based lesions. Repeat cerebrospinal fluid (CSF) flow cytometry revealed a small population of monotypic large B cells. Repeat imaging studies revealed vertebral and omental metastases. CT-guided L2 vertebral biopsy confirmed the diagnosis of diffuse large B-cell lymphoma (DLBCL) with CD20-positive, BCL-2, c-myc-negative large B cells. He was treated with highdose intrathecal methotrexate and cytarabine. © 2021 Lippincott Williams and Wilkins. All rights reserved.