Melanotic neuroectodermal tumour of infancy: Refining the surgical approach

Abstract

Melanotic Neuroectodermal Tumour of Infancy (MNTI) are particularly rare and although predominantly benign, are infiltrative and locally aggressive. Presenting in the first year of life, prompt diagnosis and effective management are critical in minimising morbidity and the risk of recurrence. A retrospective review of eleven MNTI managed at Great Ormond Street Hospital (GOSH) from 2000 to 2017 was undertaken. Eight tumours presented in the maxilla, two in the skull and one in the mandible. The primary modality of treatment was surgery in ten cases with one patient receiving neoadjuvant chemotherapy. In spite of microscopically incomplete resection in seven cases, only three recurred. Overall, there was a local recurrence rate of 27% with no distant metastases noted. Disease free survival was 100% with a follow up ranging from 0.75-17 years (median 5). Taking our results in conjunction with the available literature, there is a role for conservative initial surgery of MNTI and this should be coupled with delayed reconstruction and intensive short term follow up. We propose an adapted treatment algorithm that aims to balance the risk of recurrence and malignant change with surgical morbidity in an infant population.

A Case Report on Melanotic Neuroectodermal Tumor of Infancy and Review of the Literature

“…The condition has also occurred in older children and adults in a minority of cases [14,15]. Most publications have stated no gender predilection whilst a few have noted a slight male predominance [6,16]. It primarily develops in the head and neck region with the maxilla being the most common anatomical site affected [3,4].…”

“…The MRI scan gives the best details of the tumor itself. An isointense or hypointense lesion is imaged on T1 and T2 sequences which enhances with the administration of contrast [16,30]. Alternatively, T1 sequences can appear hyperintense if a large amount of melanin is present within the tumor [31].…”

“…Alternatively, T1 sequences can appear hyperintense if a large amount of melanin is present within the tumor [31]. An additional advantage that MRI has over CT is the lack of radiation exposure which allows the test to be repeatedly performed [16,31].…”

“…Controversy exists regarding how much bone needs to be removed in order to achieve adequate resection margins given the infiltrative growth pattern of the tumor [3]. Resection with a 2-5mm margin is often recommended once there is no functional or developmental compromise [16,24,29]. In the maxilla or mandible, the involved or adjacent teeth are also removed [14].…”

“…In the maxilla or mandible, the involved or adjacent teeth are also removed [14]. In anatomical areas such as the orbital floor, skull and sometimes the mandible; it may not be possible to achieve these margins and a more conservative resection has to be performed [16]. For these cases, enucleation and curettage of the adjacent tissue can be considered.…”