A carotid web with accumulation of myofibroblasts: a case report

Abstract

Background: Carotid webs are increasingly recognized as potential sources of ischemic stroke among young patients without conventional cardiovascular risk factors. However, its pathophysiological mechanism remains unclear. We report a case in which a carotid web was resected via carotid endarterectomy (CEA), allowing for histological analysis.

Patient presentation: In a 49-year-old male, stenosis of the left internal carotid artery occurred via magnetic resonance imaging for medical examination. Carotid ultrasonography revealed turbulent blood flow around a flap-like lesion, which was consistent with a carotid web. Because this hemodynamic disturbance may increase the risk of ischemic stroke, CEA was performed. Histopathological examination revealed intimal hyperplasia with the accumulation of myofibroblast-like cells.

Conclusion: Our pathological findings revealed intimal thickening and fibrosis and proliferation of SMA-positive, desmin-negative myofibroblast-like cells, suggesting that the dysregulation of myofibroblasts may underlie the pathogenesis of carotid webs.

Keywords: Carotid endarterectomy; Carotid web; Myofibroblast; Neural crest cell.

Fig. 1

Preoperative examination. A, B: Carotid ultrasound revealed turbulent blood flow in the left internal carotid artery (A: major axis, B: minor axis). C, D: Sagittal computed tomography angiography revealed a flap protruding from the posterior wall in both internal carotid arteries (arrow) (C: left, D: right). E-J: Magnetic resonance plaque imaging. The lesion presented with an iso-intense signal on T1-weighted imaging (WI) and hyperintensity on T2WI via plaque imaging. (E: Sagittal T1WI on the left side, F: Sagittal T2WI on the left side, G: Sagittal T1WI on the right side, H: Sagittal T2WI on the right side, I: Axial T1WI, J: Axial T2WI)

Fig. 2

Intraoperative findings of carotid endarterectomy. Microscopic view revealed a white protrusion suspected of a carotid web (arrowheads). ICA: internal carotid artery, CCA: common carotid artery

Fig. 3

Histopathology at low magnification. Histopathological specimen showing a flap-like structure made of intima hyperplasia without atheromatous findings or a thrombus (upper side: ICA; lower side: CCA) (A: H&E stain, 2 times; B: Azan stain, 2 times; C: Elastica van Gieson stain, 2 times)

Fig. 4

Histopathology at high magnification. A: H&E staining, 4x; B: H&E staining, 40x

Fig. 5

Immunohistochemistry (4 times). A: vimentin positive, B: desmin negative, C: SMA (alpha-smooth muscle actin) positive, D: cytokeratin AE1/AE3 positive, E: EMA (epithelial membrane antigen), F: S100