Melanotic neuroectodermal tumour of infancy involving the orbit and maxilla: surgical management and follow-up strategy

Melanotic neuroectodermal tumour (MNET) of infancy is a rare benign but locally aggressive tumour. We describe our surgical treatment of MNET of the orbital region. There was osteogenic relapse involving the bone of the orbit, 20 days after macroscopically complete excision of the primary tumour when the patient was 12 weeks old. This is only the second report of osteogenic relapse in MNET. The relapse was treated by excision of the involved orbital floor, preserving the orbital periosteum. The tumour has not recurred in 23 months of follow-up. Residual tumour islets may regress spontaneously after incomplete excision of MNET, but the relapse rate is between 15% and 45%. In our opinion, excising a safety margin of a few mm of apparently healthy bone reduces the risk of relapse. In contrast, the orbital contents should be preserved if they are macroscopically normal. Follow-up consisted of frequent physical examinations and CT scans.