Generalized eruptive histiocytomas and rosai-dorfman disease presenting concurrently in a patient with myelodysplastic syndrome.

Non-Langerhans cell histiocytoses were originally described as individual diagnoses. However, evidence has been mounting that these entities are manifestations on a spectrum of the same disease. The authors present a patient who initially presented with lymphadenopathy, pancytopenia, splenomegaly, and high-grade fevers. A bone marrow biopsy was performed and she was diagnosed with myelodysplastic syndrome with trisomy 8. Several months later, her persistent pulmonary lymphadenopathy was biopsied revealing Rosai-Dorfman disease. Two years after her initial hospitalization, the patient presented with lesions consistent with generalized eruptive histiocytomas. This case highlights the difficulty that clinicians encounter when trying to separate generalized eruptive histiocytomas, Rosai-Dorfman disease, and the other non-Langerhans cell histiocytoses. While further research needs to be performed in the field of histiocytoses, this case provides clinical support that these diseases are closely linked.