Localized renal artery vasculopathy: avoiding misdiagnosis between inflammatory arteritis and isolated renal artery...

Isolated renal artery involvement, whether inflammatory or dissecting, is an uncommon and challenging presentation in clinical practice. Its nonspecific symptoms and overlap with non-inflammatory vasculopathies complicate the distinction between localized vasculitis and isolated renal artery dissection (IRAD), two entities requiring fundamentally different therapeutic approaches.

We report two cases of unilateral renal artery pathology initially suspected to represent vasculitis. Case 1: A 47-year-old man presented with acute flank pain. CT and MRA revealed perivascular tissue surrounding the left renal artery, a small pseudoaneurysm, and patchy hypoperfusion. Serology, inflammatory markers, and PET/CT excluded systemic vasculitis. Corticosteroid therapy led to complete radiologic resolution, consistent with a localized idiopathic fibro-inflammatory arteritis. Case 2: A 42-year-old patient developed abrupt-onset hypertension and renal ischemia. Initial imaging suggested "sleeve-like" arterial thickening, raising concern for vasculitis. Selective angiography subsequently confirmed spontaneous renal artery dissection with thrombotic involvement of a segmental branch. The patient was managed conservatively with antihypertensives and antiplatelet therapy, achieving clinical stability and partial perfusion recovery.

These cases illustrate the diagnostic complexity of isolated renal artery disease. Normal or only mildly elevated inflammatory markers do not reliably exclude localized vascular inflammation. Advanced cross-sectional imaging and timely angiography are essential when diagnostic uncertainty persists. Misinterpretation may result in unnecessary immunosuppression or failure to recognize IRAD.

A structured, multidisciplinary evaluation integrating serologic assessment, high-resolution imaging, and close follow-up is crucial for accurate diagnosis. While isolated vasculitis may require immunosuppression, IRAD typically responds to conservative therapy, underscoring the need for individualized management.