Congenital aggressive variant of Langerhans cells histiocytosis with CD56+/E-Cadherin- phenotype.

In children <2 years of age, cutaneous involvement is the most frequent presentation of Langerhans cell histiocytosis (LCH). Cutaneous LCH can be localized or associated with dissemination and organ dysfunction. The clinical course is variable, ranging from spontaneous regression to a fatal outcome. We describe a female newborn presenting with congenital cutaneous lesions who rapidly developed pulmonary infiltrates and multiple osteolytic lesions. Skin biopsy showed a dermal infiltrate of medium to large cells morphologically and phenotypically consistent with LCH. The clinical course was rapidly fatal in spite of chemotherapy. No strict correlation between morphology and prognosis has been documented in LCH, but, in our case, distinct morphological and immunohistochemical features (CD56 expression and no E Cadherin expression) may have contributed to an aggressive clinical course.