Cutaneous pseudolymphoma following tattoo application: report of two new cases of a potential lymphoma mimicker

The authors report 2 cases of cutaneous pseudolymphoma that occurred in 2 young adult patients who referred for relentlessly growing nodules that appeared within 4 to 5 months after the application of a mercury-based tattoo. Systemic symptoms were not present and there was no evidence of lymph node enlargement. Clinically, both lesions were limited to the red, mercury-based areas of the tattoo. Microscopic examination featured a dense cellular infiltrate composed of polytypic T cells in the upper to mid-dermis, coupled with focal interface tissue reaction. Scattered macrophages contained finely granular particles in their cytoplasm. In addition, extracellular pigment particles were also recognized. Collections of epithelioid macrophages were present in both cases and were reminiscent of epithelioid granulomas. This study confirms evidence that, among skin diseases featuring a dense lymphoid infiltrate, cutaneous pseudolymphoma secondary to tattooing is a rare but not exceptional source of diagnostic challenges.