INTRODUCTION: @entity22964 of childhood often regresses spontaneously without treatment. In some cases however, it is difficult to differentiate @entity146 forms and electron microscopy and immunohistochemistry can be a valuable help. We report a case of cutaneous histiocytosis in a @entity1 which illustrates the difficulties encountered in the classification of histiocytosis. CASE REPORT: An 18-month old @entity1 was brought to consultation with a cutaneous nodule which had developed at the age of 15 months on the labia majora. A second nodule on the chin had regressed spontaneously. Histology showed evidence of dermal histiocyte proliferation. Immunohistochemistry demonstrated is non Langerhans nature which was confirmed by electron microscopy. The clinical course was benign after surgical exeresis of the lesion on the labia majora. DISCUSSION: Different forms of histiocytosis can be classed on the basis of 4 criteria: Langerhans origin or not, acquired or congenital forms, cutaneous or visceral involvement, benign or malignant course. Four diagnosis were possible in our case: histiocytosis X, self-healing congenital histiocytosis, @entity22964 , @entity6725 . We preferred to use the descriptive term of acquired regressive cutaneous non-X histiocytosis of childhood.

[Acquired regressive cutaneous non-Langerhans-cell histiocytosis in an XXXX ].

@entity1 :: ('9606', 'Species') :: ['girl', 'child'] @entity6725 :: ('MESH:D014972', 'Disease') :: ['juvenile xanthogranuloma'] @entity146 :: ('MESH:D001523', 'Disease') :: ['aggressive'] @entity22964 :: ('MESH:D015614', 'Disease') :: ['Cutaneous histiocytosis', 'benign cephalic histiocytosis']
@entity1 :: (9606,Species) :: ['infant']
