Clinicopathologic characteristics of Rosai-Dorfman disease in a medical center in northern taiwan.

Rosai-Dorfman disease (RDD) is a rare histiocytic proliferative disorder that usually presents as cervical lymphadenopathy. Extranodal involvement occurs in up to 40% of patients. The disease is most prevalent in blacks and rare in Asians. This study analyzed the characteristics of RDD in patients from Taiwan. Fourteen patients with a diagnosis of RDD were identified by review of records from 1995 to 2004 at National Taiwan University Hospital. Tissue sections from each patient were reviewed and immunohistochemical staining was performed. Data on clinical presentations, associated diseases, treatment and outcome were analyzed. In situ hybridization for Epstein-Barr virus (EBV)-encoded small RNAs (EBER-1) was also performed. Sets of primers specific for the conservative region of bacterial 16S-rDNA, IS6110 of Mycobacterium tuberculosis complex and consensus region of human herpes virus (HHV) DNA polymerase genome were used to detect the presence of these infectious agents in the specimens. There were six men and eight women with a mean age of onset of 44 years. Nine patients presented with skin lesions, four with lymph node involvement and one with nasal tumor. All lesions followed a chronic and indolent course. Most of the lesions regressed spontaneously, and no patients died as a result of this disease during follow-up. Three patients had associated immune-mediated disease, i.e. hemolytic anemia, ankylosing spondylitis and asthma. Two patients had a history of tuberculosis. Histologically, all lesions were characterized by a mixed infiltrate of large pale histiocytes, abundant plasma cells and lymphocytes regardless of the site of involvement. The strong immunoreactivities of these histiocytes to S-100 protein, CD68 and CD14 with occasional lymphophagocytosis were helpful in confirming the diagnosis, polymerase chain reaction analysis of 16S-rDNA, IS6110 and HHV gene and in situ hybridization for EBV were all negative. RDD in Taiwan is characterized by older age of onset compared to Western countries (44 years vs. 20 years) and more frequent extranodal involvement. The skin was the most common site of extranodal involvement, with about two-thirds of patients presenting with cutaneous lesions. There was no evidence of bacterial, mycobacterial or HHV infection in this series.