Spontaneous healing of Langerhans cell histiocytosis (histiocytosis X).

A 3-month-old male infant presented with pallor, hepatomegaly (4.5 cm), splenomegaly (1.5 cm), anaemia (Hb 6 g/dl) and thrombocytopenia (16 X 10(9)/l). A liver biopsy was diagnostic for Langerhans cell histiocytosis (histiocytosis X). The patient's lymphocytes, co-cultured with neonatal lymphocytes, were positive for virus-like particles without reverse transcriptase activity. The hepatomegaly diminished after 6 months and a second liver biopsy showed decreased histiocytic infiltration. A second viral blood culture remained negative. After 14 months, the hepatomegaly had disappeared completely and there were no more abnormal haematological or clinical findings.