Tibial Lymphoplasmacytic Plaque: A New, Illustrative Case of a Recently and Poorly Recognized Benign Lesion in Children

Tibial lymphoplasmacytic plaque (TLP) is a recently recognized clinicopathological entity affecting children and is characterized by a linear, reddish brown plaque on the leg with a dense dermal lymphoplasmacytic infiltrate. No effective treatments are available for this lesion of unknown etiology and its course is chronic. We report a new case in which, for the first time, a causative factor (insect bite) is strongly suspected. The clinical and pathological features of TLP may be misleading for the uninformed dermatologist or pathologist. Therefore, we would like to draw attention to this very distinctive clinicopathological presentation in order to help them recognize it easily and prevent it from being misdiagnosed as an infectious disease or, above all, a cutaneous lymphoma. We will discuss the relationship between TLP and linear acral pseudolymphomatous angiokeratoma of children, a variant of pseudolymphoma localized on acral sites in children which may share some of TLP’s histopathological features.