Title : Exclusive cutaneous form of rosai-dorfman disease : Two case reports
Abstract:
Introduction: Rosai-Dorfman disease (RDD) is a rare, benign non-Langerhans cell histiocytosis primarily affecting the lymphnodes, practically those in the cervical region. Cutaneous involvement is common and can be an initial indicator of the disease. However, diagnosing RDD based on skin manifestations is challenging and delayed
Material/methods: We report two cases of RDD with cutaneous involvement as the presenting feature. Case 1- A 26-year-old male presented with brownish-red papular nodules on the face (fig1), initially misdiagnosed as mycosis fungoides. The diagnosis took 6 months to confirm. Histological examination revealed a polymorphic inflammatory dermal infiltrate consisting of foamy histiocytes containing lymphocytes or neutrophils exhibiting emperipolesis. Immunohistochemistry showed positive expression of PS100 and CD68, but not CD1a. The patient had a pure cutaneous form of the disease. Surgical
excision was performed on selected facial lesions, while others were left untreated. The lesions spontaneously subsided after six months of follow-up. Case 2- A 32-year-old male presented with similar
brownish-red papular nodules on the face and lower back (fig2). Initially misdiagnosed as acne, the diagnosis took 2 years. Histological examination revealed a polymorphic inflammatory dermal infiltrate with evidence of emperipolesis, similar to the findings in Case 1. Immunohistochemistry demonstrated positive expression of PS100 and CD68, while CD1A was absent, also resembling the results in Case 1. The patient also had a pure cutaneous form of the disease. Local corticosteroid injections were administered to treat the facial lesions, but no improvement was observed after 12 months of follow-up.
Results (and discusssion): Both cases presented typical clinical features, such as red-brown papular nodules primarily on the face. Histological examination revealed the presence of characteristic but non-pathognomonic emperipolesis, which prompted further immunohistochemical analysis to confirm the diagnosis of RDD. Extra-cutaneous involvement was ruled out through additional examinations, including abdominal ultrasound, lymph node evaluation, bone scintigraphy, brain MRI, and eye fundus examination. Although spontaneous involutionof the disease's lesions is often observed in RDD, we
opted to initiate treatment due to the unattractive appearance of the lesions in our patients
Conclusion: Diagnosing RDD in its isolated cutaneous form can be challenging, as it often requires an anatomoclinical correlation and additional immunohistochemical studies to confirm the diagnosis.
