Rosaiª²Dorfman disease of soft tissue: A case report and literature review

    YANG Zhaoª²Rui, LU Guangª²Zhong, HU Hongª²Hui, ZHANG Yiª²Ling

    Department of Pathology, First Affiliated People¬ðs Hospital, Shanghai Jiaotong University, Shanghai 200080, China

    ¡¾Abstract¡¿ AIM: To study the pathological diagnosis, immunohistochemical features and differential diagnosis of Rosaiª²Dorfman disease (RDD) of soft tissue. METHODS: A case of RDD of soft tissue on the lower limb was investigated by light microscopy, HE stain, silver stain, Masson stain and immunohistochemical stains for Sª²100, KPª²1, MAC387, VIM, UCHLª²1, L26 and CD34, and related literatures were reviewed. RESULTS: Microscopically, the lesion consisted of abundant collagen fibrils, proliferated histiocytes and numerous infiltrated plasmocytes, lymphocytes and eosinophilic granulocytes. Fusiform or polygonal histiocytes had abundant, granular, eosinophilic cytoplasm or clear cytoplasm containing radially oriented strands or resembled xanthoma cells. Emperipolesis of numerous small lymphocytes was seen in the cytoplasm of some large histiocytes. Proliferated collagen fibrils and fusiform histiocytes formed atypical storiform pattern. Immunohistochemically, the proliferated histiocytes were positive for Sª²100, KPª²1, MAC387 and VIM. Masson stain and silver stain revealed the abundant collagen fibrils in the lesion. The histiocytes were negative for PASª²AB. CONCLUSION: RDD of soft tissue is rare and liable to be misdiagnosed in pathologic diagnosis. The histopathologic features are therefore of significance in differential diagnosis. ......