INTRODUCTION: Dysfunction of the third cranial nerve can result from lesions anywhere along its course between the midbrain and the orbit. Lymphoma is a rare cause of isolated oculomotor nerve palsy (OMP), with only 19 cases reported in the literature. We describe a case of an isolated OMP leading to the diagnosis of disseminated Burkitt lymphoma (BL).
CASE REPORT: A 37-year-old man presented with acute onset diplopia and right ptosis and was found to have a right pupillary sparing OMP. The diagnostic workout was unremarkable, including contrast-enhanced brain and orbital magnetic resonance imaging, MR angiography, exhaustive laboratory tests, and cerebrospinal fluid analysis. After a course of high-dose intravenous steroid therapy, the patient recovered almost completely. Three weeks after the discharge, he developed lumbar radicular pain and lower limbs weakness followed by the relapse of the right OMP. A second lumbar puncture revealed the presence of "small monomorphic lymphocytes," consistent with leptomeningeal lymphomatosis. A whole-body positron emission tomography scan disclosed a mediastinal mass, whose histopathologic "starry sky" appearance was pathognomonic for BL.
CONCLUSIONS: Reviewing the literature, we were able to find only 3 cases of OMP as the presenting manifestation of BL, all occurring in patients with predisposing HIV infection.Our case of isolated OMP highlights some "red flags" for a lymphomatous etiology, including young age, a progressive course, a response to high-dose steroid therapy, and relapse upon steroid discontinuation; these cases require a comprehensive evaluation, including repeated cytological cerebrospinal fluid analysis and sensitive imaging techniques to detect a possible primary lesion.