Langerhans cell histiocytosis: two clinical presentations in the same patient.

Langerhans cell histiocytosis (LCH) is a heterogeneous group of diseases characterized by a pathological proliferation of cells phenotypically similar to Langerhans cells. The disease course is variable, alternating between resolving and potentially fatal forms. The diagnosis is based on clinical appearance and confirmed by CD1a positivity and / or immunohistochemistry. We report the case of a male child of 3 months with two different presentations of Langerhans cell-histiocytosis (LCH) at different times. The first presentation was classified as a self-healing LCH (formerly known as Hashimoto-Pritzker). The last presentation, although clinically suggestive of Letterer-Siwe (former designation), was not associated with systemic disease. This emphasizes that LCH cannot be compartmentalized into four groups, but considered a single disease with a wide spectrum of clinical presentations. This case underscores the importance of frequent and long-term follow-up of these patients.