Congenital Histiocytosis: A Heterogeneous Group of Diseases, one Presenting as So-Called Congenital Self-Healing Histiocytosis
Abstract
Three cases of congenital histiocytic disorders - generalized Langerhans cell histiocytosis, generalized juvenile xanthogranuloma and so-called congenital self-healing histiocytosis are compared using histiochemical, immunohistochemical and ultrastructural methods. The results showed a typical morphological pattern of Langerhans cell histiocytosis (S 100+, CD 1+, alpha-mannosidase +) with an unusual self-healing cutaneous phenomenon.
The congenital self-healing histiocytosis showed a non-Langerhans cell immunophenotype (CD 14+, CD 1-, S 100-) and morphological appearance resembling the evolutive "early" stage of juvenile xanthogranuloma. A diffuse cellular positivity of alpha-mannosidase in juvenile xanthogranuloma and congenital self-healing histiocytosis differed from a typical perinuclear globular positivity of this enzyme in Langerhans cell histiocytosis.
It is concluded that congenital self-healing histiocytosis may in some cases be of non-Langerhans cell type and under this term a clinically characteristic syndrome of histiocytic proliferation of Langerhans cells or tissue histiocytes may be included.