Macular lymphocytic arteritis: Clinical-pathologic correlation of a rare vasculitis

LTA: lymphocytic thrombophilic arteritis MLA: macular lymphocytic arteritis NBUVB: narrow-band ultraviolet B INTRODUCTION Macular lymphocytic arteritis (MLA) and lymphocytic thrombophilic arteritis (LTA) are terms used to describe an indolent, cutaneous medium-vessel vasculitis that has been suggested to follow a benign but persistent disease course. Pathologically, this condition is characterized by medium-vessel vasculitis composed primarily of lymphocytes and notably lacking neutrophils, thus distinguishing it from cutaneous polyarteritis nodosa. Clinically, published cases have typically presented with macules, papules, livedoid patches, and ulcerations on the lower extremities, and to date, no cases have described progression to systemic vasculitis. Our understanding of the clinical presentation, pathophysiology, and treatment of MLA/LTA is lacking, which is largely attributable to the rarity of the condition and the unfamiliarity of providers. When performed, histology alone may result in a diagnosis of polyarteritis nodosa or other mediumvessel vasculitis. The pathology likely causes confusion, as the benign clinical presentation appears incongruent with the largely obliterative vasculitis seen under the microscope. In this vein, treatments have ranged from systemic immunosuppression to supportive care mirroring the dichotomous clinical and pathologic findings. Herein, we describe 4 additional cases of this rare vasculitis (Table I) and discuss the clinicalpathologic correlation. We also present the second