Intralymphatic histiocytosis overlying hip implantation treated with pentoxifilline

Intralymphatic histiocytosis (IH) is a rare condition that presents with livedoid, erythematous to violaceous patches and plaques near affected joints most commonly in patients with rheumatoid arthritis and in at least 8 reports overlying metal implants. We report the case of a 58 year-old Caucasian woman who developed an indurated violaceous reticulated plaque overlying her right hip after placement of a metal hip implant 6 years prior for treatment of osteoarthritis. Histopathology revealed a proliferation of D2-40-positive dilated lymphatic spaces in the dermis and intralymphatic proliferation of CD68-positive histiocytes. Lab results included negative serology for rheumatoid factor and negative leukocyte function testing for metal allergies. The patient was treated with pentoxifylline, which resulted in decreased induration and erythema of the lesion with almost complete resolution of the plaque. This case highlights the diagnostic and therapeutic challenges of cutaneous reactive angiomatoses, which are rare skin conditions that can present with similar clinical and histologic findings and can be differentiated on the basis of immunostains that highlight vascular and lymphatic endothelium and histiocytes. Pentoxifylline may be considered as a therapeutic option because of its anti-inflammatory and antiplatelet activity.