Rare Case of Cutaneous Rosai Dorfman Disease Involving the Nail

Abstract Introduction/Objective Rosia-Dorfman Disease (RDD) is a rare benign non-Langerhans cell histiocytic disorder of unknown etiology with heterogeneous clinical features. RDD was first described by Destombes in 1965 under the term “adenitis with lipid excess.” However, it is named after Rosai and Dorfman, who characterized the further histopathological features of the disease in 1969. The characteristic presentation of RDD is lymphadenopathy, and extra nodal sites include bone, upper respiratory tract, central nervous system, retroperitoneum, and skin. The management of RDD depends on the site of involvement and the presence or absence of the symptoms. Multifocal and refractory diseases require systemic treatment. Surgical resection can be considered in symptomatic and resect- able diseases. Methods/Case Report A 16-year-old Asian female with no significant past medical history presented with a painful verrucous lesion on the left 5th finger for one year with bleeding and purulent discharge. Excision was performed, and histologically, there was extensive infiltration of large histocytes in the dermis with occasional lymphocytes and plasma cells. The histiocytes were engulfing the intact inflammatory cells, exhibiting the emperipolesis phenomenon. Immunohistochemically, S100 and CD68 were positive in the large histiocytes, and leukocyte common antigen (LCA) was positive in the background lymphocytes. Based on histology and immunohistochemistry, RDD diagnosis was rendered. Results (if a Case Study enter NA) N/A Conclusion RDD is a rare condition that poses challenges in diagnosis and management. The key diagnostic factors are histological features and immunohistochemistry to exclude other pathological disorders. Treatment should be tailored according to the needs of each patient and as required to optimize the outcome. We recommend an appropriate diagnosis of this entity in a timely manner to prevent any further long-term complications.