Rosai-Dorfman disease is a rare disease that manifests with painless cervical lymphadenopathy, fever, anemia, an elevated erythrocyte sedimentation rate (ESR), and hypergammaglobulinemia. Extranodal lesions occur in 1/3 of patients, and the skin is involved in more than 10% of cases. Purely cutaneous disease is uncommon and only about more than 100 cases have been reported. Cutaneous Rosai-Dorfman Disease (CRDD) appears to be a distinct entity with different age and race predilection from cases with lymph node involvement.
This is a case of a 40-year-old Filipino female who presented with multiple erythematous papules and plaques with pustules on the cheeks. Skin punch biopsy showed a dense dermal infiltrate of polygonal histiocytes with abundant cytoplasm and vesicular nuclei. Emperipolesis was also present. The histiocytes were highlighted by the immunohistochemical stains S-100 and CD68 and was CD1a negative. Complete blood count and ESR were normal. Cervical lymphadenopathy was absent. Findings were consistent with Cutaneous Rosai-Dorfman disease. The patient was started on methotrexate at 15mg/week with folic acid supplementation. Mild soap, benzoyl peroxide 5% gel and tretinoin 0.05% cream once daily were maintained during the treatment course. There was significant decrease in erythema and size of existing lesions after 2 months. The patient was referred to a hematologist for monitoring of possible future systemic involvement.
Because of its rarity, clinicopathological correlation is always mandatory to establish a diagnosis of CRDD. Immu nohistochemical stains are required to differentiate this entity form other forms of Langerhans cell histiocytosis. Multidisciplinary referral is required to rule out concomitant systemic involvement.