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Giant cell arteritis (GCA) is the most common vasculitis in individuals 50 years or older, with a lifetime risk in the United States of 1% in women and 0.5% in men. It is a granulomatous disease that affects large- and medium-sized vessels, most notably the branches of the internal and external carotid arteries. GCA can cause both afferent and efferent visual manifestations, the most common being arteritic anterior ischemic optic neuropathy. Diagnosis of GCA is made using criteria developed by the American College of Rheumatology, which include clinical signs, positive biopsy, and elevated erythrocyte sedimentation rate. C-reactive protein and platelet counts may be elevated in GCA, and noninvasive imaging modalities such as Doppler ultrasound and magnetic resonance imaging are now being used to aid in diagnosis. While glucocorticoids are the mainstay of treatment for GCA, new breakthrough treatments such as tocilizumab (an anti-IL-6 receptor antibody) have shown great promise in causing disease remission and reducing the cumulative glucocorticoid dose. Emerging therapies such as abatacept and ustekinumab are still being studied and may be of use to clinicians in the future.

Castleman disease (CD) is a rare lymphoproliferative disorder that may present with various autoimmune, inflammatory, or neurologic syndromes. This is a case of a 21-year-old woman who presented with signs and symptoms of pseudotumour cerebri (PTC) who subsequently developed myasthenia gravis (MG), and was incidentally found to have a large mass in the posterior mediastinum. Upon resection, the mass was classified as unicentric CD involved with follicular dendritic cell sarcoma. Following treatment with IVIG in the setting of progressive weakness and dyspnea, she has had complete symptom resolution while maintained on a low dose of pyridostigmine for the last two years. There are 13 cases of MG and five cases of optic disc edema described as PTC associated with CD in the literature, but to our knowledge, this is the sole case reported of the intersection of all three conditions in one patient. Increased serum levels of interleukin-6 and vascular endothelial growth factor may provide clues as to the association of CD with these neurologic syndromes.

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A 74-year-old man with chronic obstructive pulmonary disease, glaucoma, and Stage IIIB squamous cell lung cancer experienced several minutes of flashing lights in his right visual hemifield, followed by onset of a right visual field defect. On examination, the patient had a right homonymous hemianopsia that was most dense inferiorly by confrontation testing. Emergent CT scan of the head revealed a 2.5 × 3 cm hypodensity in the left occipital lobe, which was interpreted as an acute stroke. Continuous EEG monitoring captured left posterior quadrant seizures that were temporally correlated to the positive visual phenomena. Subsequent MRI of the brain with and without contrast revealed a conglomerate of centrally necrotic and peripherally enhancing mass lesions. On biopsy, a thick purulent material was drained and Gram stain of the sample revealed gram-positive beaded rods, which speciated to Nocardia farcinica. The patient was treated with a six-week course of intravenous meropenem and a one-year course of oral trimethroprim–sulfamethoxazole. On follow-up, the patient experienced resolution of the right visual field deficit.