Histological variability and the importance of clinicopathological correlation in cutaneous Rosai-Dorfman disease

Rosai-dorfman disease is a benign histiocytic proliferative disorder of unknown etiology. the disease mainly affects lymph node tissue,although it is rarely confined to the skin. here,we describe a 53-year-old woman with purely cutaneous rosai-dorfman disease. the patient presented with a large pigmented plaque on her left leg,and sparse erythematous papules on her face and arms. a complete clinical response was achieved with thalidomide,followed by recurrence at the initial site one year later. the histological examination displayed the typical features of rosai-dorfman disease in the recent lesions but not in the older lesions. in the setting of no lymphadenopathy,the histopathological features of rosai-dorfman disease are commonly misinterpreted. therefore,awareness of the histological aspects present at different stages,not always featuring the hallmark microscopic signs of rosai-dorfman disease,is particularly important for a correct diagnosis of this rare disorder. © 2016 by anais brasileiros de dermatologia.