Polyarteritis Nodosa Presenting as Temporal Arteritis in a 9-Year-Old Child

9-year-old girl with left-sided monocular blindness and frontal headaches associated with tenderness over the temporal region.

A, Noncontrast CT scan shows an enlarged and dense left temporal artery (arrow). Bone window algorithm (not shown) and HU measurement showed no evidence of calcification.

B, Digital subtraction angiogram, anteroposterior view from a left common carotid injection, shows focal, long-segment stenosis (arrows) and beading (arrowheads) of the left superficial temporal artery.

C–E, Biopsy findings of the left temporal artery. Low-power view (C) shows focal irregularity and near circumferential fibrinoid necrosis in the biopsy specimen (arrows). Note the clot within the lumen of the vessel (hematoxylin-eosin; original magnification ×10). Cross section of the superficial temporal artery (D) shows marked intimal hyperplasia (straight arrows) with disruption of the internal (open arrow) and external (curved arrow) elastic membranes (elastin; original magnification ×40). High-power view of the vessel media (mid wall) (E) shows a mixed cellular lymphocytic-predominant infiltrate (arrows) (original magnification ×100).

F and G, Contrast-enhanced T1-weighted (800/20/4) (F) and T2-weighted (2000/200/1) (G) axial brain MR images (obtained after clinical relapse, including bilateral blindness, mental status changes, and abdominal pain) show multiple peripheral focal areas of contrast enhancement and T2 prolongation involving the frontoparietal cortex (arrows).

H, Digital renal angiogram obtained 1 day after the MR study shows multiple peripheral microaneurysms (arrows), consistent with systemic PAN.