OBJECTIVETo investigate the clinicopathologic features, diagnosis, differential diagnosis of multiple Rosai-Dorfman disease (RDD).

METHODSSeven cases of multiple RDD were treated in Fujian Provincal Hospital and Fuzhou General Hospital of Nanjing Military Command of Chinese PLA. The disease was analyzed, focusing on the process of diagnosis, the treatment and follow-up. Histopathology, immunohistochemical profiles and relative literature were reviewed to reveal the characteristics of this disease.

RESULTSThe seven cases, occurred in 3 women and 4 men from 18 to 60 years of age (median 45.71 years), with masses measured of 0.8-6.0 cm (average size of 3.0 cm). Masses located in, left subcutaneous arm, thyroid, paratrachea, left maxilla, right subcutaneous cheek, left subcutaneous chest wall, right subcutaneous inguina, bilateral subcutaneous neck, right tibia, right thigh skin, right frontal lobe of brain, cerebral parafalx and bilateral lymph nodes of the neck, respectively. Among the cases, from the first case to the sixth case were extranodal tissue, and the seventh case was located in lymph nodes. Cases showed progressive increase of the mass. Histologically, all lesions of seven cases were similar with nodular structures presenting with alternating hyper- and hypo-cellular areas. The hypo-cellular areas revealed lymph-sinustoid structure characterized by variable numbers of large histiocytes, which had an abundant cytoplasm, pale to eosinophilic in appearance, phagocytozed intact lymphocytes or emperipolesis. While hyper-cellular areas revealed the infiltration of lymphocytes, plasma cells, neutrophils and numerous collagen fiber. Two cases also revealed the infiltration of lymphoid follicles. Immunohistochemically, the large histiocytes were strongly positive for S-100, CD163 and CD68 protein.

CONCLUSIONSMultiple RDD is rare. In clinic and pathology, it needs to be differentiated from granulomatous diseases, IgG4-related sclerotic diseases, inflammatory myofibroblastic tumor, fibrohistiocytoma, Langerhans cell histiocytosis, and so on. The primary approach of treatment for multiple RDD is complete surgical excision and its prognosis is good.