Sinus histiocytosis clinically limited to the skin

Sinus histiocytosis with massive lymphadenopathy is a rare clinicopathologic entity that affects mainly children and young adults. Although the lymph nodes are the most common sites of involvement, extranodal infiltrates may arise in the orbits, skin, upper respiratory tract, and bone, as well as other organs. Approximately 10% of patients have had cutaneous infiltrates, but very few of them have had lesions limited to the skin. We treated a 15-year-old female with cutaneous nodules as the sole manifestation of the disease.