<p>Polyarteritis nodosa (PAN) is a systemic necrotizing vasculitis of medium-sized arteries, and histologic confirmation is often challenging. Temporal artery biopsy (TAB) is established for suspected giant cell arteritis (GCA), but is rarely performed in PAN. We describe a 27-year-old Japanese man who presented with melena and acute visual loss in the right eye. Contrast-enhanced computed tomography revealed multiple visceral aneurysms involving the hepatic, renal, and mesenteric arteries, with active extravasation from a jejunal artery aneurysm. Ophthalmologic evaluation confirmed central retinal artery occlusion. Renal biopsy showed no evidence of vasculitis. During hospitalization, he developed a new medullary infarction, and re-examination revealed induration of the superficial temporal artery. TAB was therefore performed and demonstrated neutrophil-rich necrotizing arteritis with fibrinoid change, supporting the diagnosis of PAN. To contextualize the diagnostic role of TAB in PAN, we reviewed the literature and identified 21 TAB-confirmed cases including this patient. Most reported TAB-confirmed PAN cases underwent biopsy because GCA was initially suspected, and the histopathologic findings were heterogeneous; a neutrophil-predominant necrotizing pattern with fibrinoid change—particularly in the absence of multinucleated giant cells—may prompt reconsideration beyond GCA. The diagnostic yield of TAB in unselected PAN has not been studied, and the available evidence is limited to case reports and TAB-based cohorts. Nevertheless, TAB may be considered a pragmatic option for histologic confirmation when conventional biopsy sites are impractical or high risk, particularly in the presence of cranial ischemic manifestations or temporal-artery abnormalities.</p>