Melanotic neuroectodermal tumor of infancy: report of one calvarial lesion with T1 shortening and one maxillary lesion

Clinical and imaging features of melanotic neuro-ectodermal tumor of infancy of the maxillary bone: report of four cases and review of the literature

Melanotic neuro-ectodermal tumor of infancy (MNTI) is an extremely rare tumor. The purpose of this study was to describe the imaging features of maxillary bone MNTIs and introduce the key points for clinical diagnosis of MNTI. We retrospectively reviewed four patients with histology-proven MNTIs arising from the maxillary bone. All patients underwent ultrasonic inspections, CT and/or MR scanning. Combined with previously literature, the imaging features were comprehensively evaluated and analyzed. All MNTIs showed a firm, non-ulcerated rapidly-growing soft-tissue swelling with pigmented (blue-colored or black-colored or gray-colored) mucosa. The onset ages were younger than 6 month-old. CT images showed osteolytic or expansive bone destruction of the involved maxillae, fragmentary cortical bone, "free-floating" tooth germs, with or without spiculated/sunburst periosteal reaction. The tumor appeared lightly hyper-intense on T2-weighted sequences, while isointense or lightly hypo-intense or lightly hyper-intense signal on T1-weighted sequences. Enhanced images all displayed heterogeneous enhancement. No metastasis features of lymph nodes or abdominal organs were demonstrated by cervical and abdominal ultrasonic inspections. As a conclusion, accurate recognition of the imaging features of MNTI combined with history and clinical manifestations (early infancy, painless, firm, pigmented mucosa, non-ulcerating lesion) can provide clues for diagnosis of this rare entity.

Melanotic neuroectodermal tumor of infancy arising from the skull: report of an unusual case, review of the literature, and a diagnostic approach

INTRODUCTION

Melanotic neuroectodermal tumor of infancy is a rare neoplasm mainly seen in children under 1 year of life. The most common location of the tumor is the maxilla followed by the cranial vault. Surgery is the treatment of choice and outcome mainly depends on extent of resection.

OBJECTIVES

To report an atypical case of an 8-year-old patient with a melanotic neuroectodermal tumor of infancy, to review the cases with melanotic neuroectodermal tumor of infancy arising from the skull published over the last 13 years, and to provide a diagnostic approach that may allow recognition of a pattern in these rare neoplastic lesions.

METHODS

A case is reported with a description of the clinical, radiological, surgical, and histopathological features. Additionally, the literature was reviewed to identify reports of patients with melanotic neuroectodermal tumor of infancy arising from the cranial vault and all cases published in PubMed over the last 13 years were included. Only studies that evaluated clinical, radiological, surgical, and histopathological findings were included.

CONCLUSION

Melanotic neuroectodermal tumor of infancy is a rare entity that may present with unusual features, but nevertheless has an identifiable pattern that allows the tumor to be considered in the differential diagnosis of intracranial space-occupying lesions in children.

Extensive Melanotic Neuroectodermal Tumor of Infancy

The melanotic neuroectodermal tumor of infancy (MNTI) is a rare childhood neoplasm with an alarming but classical clinical presentation. We present the case of a 2-month-old male infant treated with surgery for an aggressive MNTI on the alveolar process of the maxilla. Radiographic examination showed a diffuse osteolytic radiolucent lesion in the right maxilla, and displacement and dysmorphic changes in the developing primary tooth buds. The patient remained well without evidence of recurrence for 6 months after surgery. We discussed clinicopathological features, management alternatives, and outcome.

Melanotic neuroectodermal tumor of infancy arising in the temporal bone

Melanotic neuroectodermal tumor of infancy is a rare melanin-containing neoplasm with locally aggressive and rapid expansile growth, usually involving the maxilla, skull, and mandible of early infancy. Radical surgery is critical for a long-term outcome. We present a case of 14-month-old girl with rapid-growing subcutaneous mass arising in the right temporal bone and extending intracranially on computed tomographic scan. Radical surgery was performed. A brownish-black tumor composed of large pigmented epithelioid cells, positive for cytokeratins and HMB-45, and nests of small neuroblast-like cells positive for neuron-specific enolase and synaptophysin, was diagnosed as melanotic neuroectodermal tumor of infancy. The patient remained well without evidence of recurrence for 1 year after surgery. Clinicopathological features, management alternatives and outcome were discussed.

Histologic validation of locus coeruleus MRI contrast in post-mortem tissue

The locus coeruleus (LC) noradrenergic system regulates arousal and modulates attention through its extensive projections across the brain. LC dysfunction has been implicated in a broad range of neurodevelopmental, neurodegenerative and psychiatric disorders, as well as in the cognitive changes observed during normal aging. Magnetic resonance imaging (MRI) has been used to characterize the human LC (elevated contrast relative to surrounding structures), but there is limited understanding of the factors underlying putative LC contrast that are critical to successful biomarker development and confidence in localizing nucleus LC. We used ultra-high-field 7 T magnetic resonance imaging (MRI) to acquire T1-weighted microscopy resolution images (78 μm in-plane resolution) of the LC from post-mortem tissue samples. Histological analyses were performed to characterize the distribution of tyrosine hydroxylase (TH) and neuromelanin in the scanned tissue, which allowed for direct comparison with MR microscopy images. Our results indicate that LC-MRI contrast corresponds to the location of neuromelanin cells in LC; these also correspond to norepinephrine neurons. Thus, neuromelanin appears to serve as a natural contrast agent for nucleus LC that can be used to localize nucleus LC and may have the potential to characterize neurodegenerative disease.

Melanotic neuroectodermal tumour of infancy: CT and MR findings

BACKGROUND

Melanotic neuroectodermal tumour of infancy (MNTI) is a rare neoplasm of neural crest origin.

OBJECTIVE

To describe three further cases of MNTI, with emphasis on CT and MRI findings.

MATERIALS AND METHODS

Data for children with histologically confirmed MNTI following biopsy or surgery were retrieved. Three children with available imaging at the time of diagnosis were included in the study.

RESULTS

All three children had primary tumour in the head and neck region: one in the maxilla, one in the occipital bone (extra-axial but with intracranial extension) and one with an unusual tumour growing exophytically from the subcutaneous tissues adjacent to the occipital bone. All tumours were iso/hypointense both on T1- and T2-weighted MRI, and showed marked contrast enhancement in their non-ossified components. CT allowed identification of bone destruction and remodelling.

CONCLUSION

Our findings are consistent with previously reported cases of MNTI regarding age at presentation and location in the head and neck region. Our MR findings did not demonstrate the typical pattern of T1-shortening expected from melanin deposition.

Melanotic neuroectodermal tumour of infancy: report of two cases and review of the literature

Melanotic neuroectodermal tumour of infancy (MNTI) is an uncommon tumour affecting predominantly the craniofacial bones of the newborn infants. The neural crest origin of the tumour has been confirmed. MNTI is generally accepted as a benign tumour despite of its rapid and locally infiltrative growth. Recurrence rate varies between 10% and 60%, and malignant behaviour has been reported in 6.5% of MNTIs. Systematic review of the literature revealed 445 MNTIs published between 1918 and 2010. We present additional two cases of MNTI from our Department, typical in all terms, which equals a total number of 447 reported cases. One of our cases revealed histological features consistent with malignant behaviour, but at present, 18 months after the surgical excision, there is no evidence of recurrence. Biological behaviour of MNTI cannot be predicted by gross or histologic characteristics, thus early diagnosis and careful follow-up after the complete surgical excision is required.