p e d i a t r i a p o l s k a 9 0 ( 2 0 1 5 ) 7 6 -8 0 i n f o r m a c j e o a r t y k u l e Historia artykułu: Słowa kluczowe: histiocytoza z komórek Langerhansa postać wieloukładowa LCH trudności diagnostyczne a b s t r a c t Langerhans cell histiocytosis (LCH) is a rare disease of unknown etiology and varied picture and clinical course. The intensity and the outcome of LCH treatment depend on the amount and type of the affected organs, their dysfunction and age of the patient.In this paper we present the diagnostic difficulties in a 19-month-old girl with multisystem LCH, manifesting mainly by persistent fever, deep anemia, hepatosplenomegaly and lymphadenopathy, coexisting with EBV infection and urinary tract infection. On diagnosis, LCH was suspected once the bone lesions were detected on CT scans, which, however, were not confirmed in the bone scintigraphy. Histopathological diagnosis of LCH was based on the histopathological examination of the cervical lymph node, in which CD1a expression was detected. Myelogram morphologically was assessed as normal; however, bone marrow smears were respectively found to express CD1a. The