Emperipolesis is not pathognomonic for Rosai-Dorfman disease: Rhinoscleroma mimicking Rosai-Dorfman disease, a clinical series

摘要

Case 1, a 57-year-old man, presented with 1 tender nodule on right perioral skin for 2 weeks. Neither cervical lymphadenopathy nor fever was observed. Clinical impression was an inflamed epidermal cyst. An incision revealed only minimal serous discharge. Further skin biopsy specimen showed mixed inflammatory cells, some of which were phagocytosed by foamy histiocytes (emperipolesis) (Fig I, A). Because common clinical features of fever and cervical lymphadenopathy were absent, the diagnosis of RDD was questioned. Further examination showed these foamy histiocytes negative for S-100 and CDla, but positive for CD68, contradicting the diagnosis of RDD. Giemsa stain revealed aggregated short rod bacilli within the histiocytes (Fig 1, B). The tissue cultures grew K pneumoniae. The diagnosis of rhinoscleroma was rendered based on the demonstration of bacilli, CD68+ histiocytes, and growth from the tissue culture.