LAUSR

BACKGROUND Cutaneous Rosai-Dorfman (CRD) disease is a rare entity that is characterized by histiocytic proliferation in the skin. The disease has been reported to exhibit different clinical profiles and occasionally confounding histologic features that may be challenging for a correct diagnosis. The purpose of this study was to assess the pathobiology and highlight the variance in clinical and histologic spectrum of the disease based on published literature. METHODS A PUBMED search was performed to retrieve cases of cutaneous Rosai-Dorfman disease published in the literature. A PRISMA-guided review of the included articles was performed. Three interesting case reports from our institution are also described. RESULTS A total of 263 patients, of which 220 with purely cutaneous disease were identified in 152 studies. The mean age at presentation was 45.2 years with a slight female preponderance, and East-Asian, Caucasian and African populations being largely affected. Majority of the patients presented with multiple lesions, predominantly on limbs and comprising of nodules, plaques and papules that were occasionally pigmented. The classis histologic findings included large foamy histiocytes, exhibiting emperipolesis and a specific immunophenotype (S100+, CD68+, CD1a-). Inconspicuous emperipolesis, fibrosis, increased vascularity, neutrophilic microabscesses and concurrent langerhans cell histiocytosis and lymphoma in few cases highlighted the importance of immunohistochemistry for a definitive diagnosis. The disease shows an indolent and benign course with excision and chemotherapy being most effective for extensive and refractory cases. CONCLUSIONS This review of largest cohort of CRD patients provides an updated insight into the clinicopathologic features with possible diagnostic pitfalls and effective therapeutic options that should be useful in diagnosis, management and future research opportunities.