[Juvenile xanthogranuloma: a form of histiocytosis with an excellent prognosis].

In three patients, a girl aged six weeks and two boys aged eight and three months, juvenile xanthogranuloma was diagnosed. This is a rare cutaneous disorder that predominantly occurs during infancy and early childhood. It is one of the non-malignant, non-Langerhans cell histiocytoses (class II histiocytoses). It is characterized by a circumscript, firm, yellow-brown and sometimes pink-red nodule or papule located mainly on the face or scalp. Diagnosis can be made on the clinical appearance. However, this may need to be confirmed by a histopathological investigation, which includes immunohistochemical stains. In contrast to generalized histiocytoses, the prognosis of juvenile xanthogranuloma is excellent: the cutaneous tumour disappears spontaneously in one to six years. However, extracutaneous involvement, which is most frequently located in the eye, can occur. Moreover, juvenile xanthogranuloma is associated with neurofibromatosis type I and juvenile chronic myeloid leukaemia. This rare but possibly life-threatening systemic involvement justifies meticulous follow-up.