Masquerades of Giant Cell Arteritis Evident on Temporal Artery Biopsy

Abstract

G iant cell arteritis (GCA) is a systemic vasculitis that affects large-and medium-sized blood vessels in patients over 50 years of age. 1 Patients with GCA typically present with systemic symptoms such as headache, fatigue, fever, jaw claudication, scalp tenderness and vision changes. The gold standard for establishing the diagnosis of GCA is a temporal artery biopsy, which helps confirm the diagnosis and justify long-term corticosteroids in patients who are frequently elderly with significant medical comorbidities and who may experience substantial steroid-related side effects. 2 Signs of GCA seen on temporal artery biopsy include a panarteritis consisting of infiltrates of T-lymphocytes, macrophages, epithelioid histiocytes and multinucleated giant cells, often most pronounced in the media and centered near the internal elastic lamina, with fragmentation of the internal elastic lamina, intimal hyperplasia, and near or complete occlusion of the temporal artery lumen. 2 These signs may be present even after treatment with corticosteroids. 3 Temporal artery biopsy may not only confirm the diagnosis of GCA, but may also identify atypical histopathological signs that suggest another diagnosis. These signs include fibrinoid necrosis, inflammation confined to the adventitia, numerous eosinophils or neutrophils, or abnormal deposits such as amyloid. 4 These atypical signs would not be evident on alternative, non-invasive methods of assessing the superficial temporal artery such as color-duplex ultrasonography or contrast-enhanced, high-resolution magnetic resonance imaging (MRI), which have been suggested as replacements for temporal artery biopsy in typical cases. 5,6 The specificity of ultrasound and high-resolution MRI have been reported to be 78-100% and 73-97%, respectively, for GCA. 5 Given that the necessity of temporal artery biopsy in the diagnosis of GCA has been questioned, 5,7,8 we present three cases of patients who presented with visual and systemic symptoms suggestive of GCA who underwent temporal artery biopsy, which revealed an alternative diagnosis to GCA and dramatically altered the patient's treatment and clinical care.

Optic nerve head plasmacytoma as a manifestation of multiple myeloma

“…[ 9 12 ] Hyperviscosity syndrome created by excess monoclonal immunoglobulins can impair microvascular circulation, leading to downstream ischemia and optic neuropathy. [ 9 13 14 ] The optic nerve can also be infiltrated directly by malignant plasma cells. [ 9 ] Lastly, extramedullary plasmacytomas are soft-tissue plasma cell tumors that can occur as primary or secondary processes which can cause direct mass effect on the optic nerve.…”