The cellular proliferations of the skin, especially malignant tumors, are rare in children as compared with adults. However, such proliferations are concentrated in the first months of age (Fig. 790). According to some Authors (25), this is why in the neonatal period whatever tumefaction of doubtful diagnosis should induce to rule out tumors.
Characteristically, the proliferations of the first months present a very wide clinical spectrum, ranging from an isolated cutaneous lesion to the generalized involvement of the skin till the multisystem involvement. Their prognosis is also very variable, ranging from the spontaneous regression to the exitus. The tendency to the spontaneous regression is much higher at this age. It does not depend on the cell type affected, being practically detectable in all the neonatal proliferations, both benign and malignant, from hemangioma to mastocytoma, to juvenile xanthogranuloma, myofibromatosis, Langerhans cell histiocytosis and neuroblastoma. (...).