Congenital plexiform neurofibroma with a sarcomatous nodule in a three month old child.

Congenital plexiform neurofibroma is regarded as pathognomonic of neurofibromatosis (NF) especially when it is large and involves a major nerve trunk with changes of elephantiasis neuromatosa. Only very rarely malignant changes have been reported in cases who have NF for less than 5 years. 'Borderline' lesions are seen especially in patients with NF. In such cases criteria of mitotic activity should be utilized in establishing the diagnosis of malignancy. A case of 3 month child with congenital plexiform neurofibroma involving neck with elephantiasis neuromatosa with sarcomatous nodule has been described in the present article. The criteria for malignancy in nerve sheath tumors have also been discussed.