A clinicopathologic and immunohistochemical analysis of melanotic neuroectodermal tumor of infancy

Melanotic neuroectodermal tumor of infancy (MNT1) arising in the skull. Short review of two cases

INTRODUCTION

Melanotic neuroectodermal tumor of infancy (MNT1) is a rare congenital pigmented neoplasm of neural crest origin, locally aggressive, and rapidly growing that develops during the first year of life. It most commonly arises from the maxilla, the cranial vault, and the mandible. Early diagnosis and radical surgery are critical for a long-term outcome.

METHODS

A literature search through PUBMED revealed 43 cases of MNT1 arising in the skull. We reviewed the available literature and studied the presenting symptoms, diagnostic procedures, treatment, rates of recurrences, malignancy, and data of follow-up. We report two further cases of infants aged 4 and 10 months, respectively, with MNT1 arising from the cranial vault who underwent radical excision of the lesion.

CONCLUSION

Melanotic neuroectodermal tumor of infancy should be included in the differential diagnosis of skull lesions in infants. Radical surgery must be considered as the treatment of choice and close follow-up for at least 2 years is necessary.

Melanotic neuroectodermal tumor of infancy in oral cavity at unusual age

The melanotic neuroectodermal tumor of infancy is an extremely rare, fast-growing but benign lesion, commonly occurring in the maxilla of children within the first year of life. Only about 380 cases of this particular tumor have been documented in the medical literature and very few of them have been reported to have occurred in late childhood. We describe here a relatively uncommon presentation of melanotic neuroectodermal tumor of infancy of maxilla arising from palatal gingiva of a 10 year-old female, its course and management by surgical excision with safe margins.

Melanotic neuroectodermal tumor of infancy: discussion of a case and a review of the imaging findings

Melanotic neuroectodermal tumor of infancy (MNTI) is an uncommon melanin-containing mesenchymal tumor of neural crest origin. What make this tumor unique and interesting is its characteristic predilection for anterior maxilla (premaxilla) and the presence of pigment melanin which gives the tumor distinct clinicopathological, immunohistochemical, ultrastructural and imaging features. Although first described almost a century ago, to the authors’ knowledge, only a few hundred cases of MNTI have been reported worldwide in the English medical literature. The pool of documented radiological findings is even more sparse as not more than a dozen cases could be abstracted from an Internet search of the radiology literature. We document a case of MNTI and describe the imaging findings with intent to contribute to its small but accruing radiological data.

Pigmented lesions of the central nervous system: radiologic-pathologic correlation

Pigmented lesions of the central nervous system (CNS) are a diverse group of entities that run the gamut from benign to malignant. These lesions may be well circumscribed or diffuse, and their imaging appearances are influenced by the degree of melanin content as well as the presence or absence of hemorrhage. Pigmented lesions include primary melanocytic lesions of the CNS and metastatic melanoma, as well as other CNS neoplasms that may undergo melanization, including schwannoma, medulloblastoma, and some gliomas. Primary melanocytic lesions of the CNS arise from melanocytes located within the leptomeninges, and this group includes diffuse melanocytosis and meningeal melanomatosis (seen in neurocutaneous melanosis), melanocytoma, and malignant melanoma. Primary melanin-containing lesions of the CNS must be differentiated from metastatic melanoma because these lesions require different patient workup and therapy. Absence of a known primary malignant melanoma helps in the differential diagnosis, but an occult primary lesion outside the CNS must be sought and excluded. Pigmented lesions of the CNS are uncommon, and knowledge of their imaging characteristics and pathologic features is essential for their identification.

Lesions of the jaws

The jaws differ in various aspects from all other bones in the skeleton. Embryologically, they are for the major part derived from migrating cells of the cranial neural crest, the so-called ectomesenchyme, and not merely from mesoderm, and they contain teeth. This latter point, especially, results in the presence of lesions that are not found in other bones, a broad variety of odontogenic cysts and tumours. They will be the major topic of this review. Other lesions, not strictly odontogenic but also mainly confined to the jaw bones, are giant cell lesions, fibro-osseous lesions, and the melanotic neuro-ectodermal tumour of infancy. They also will be included in this overview.

Recurrent melanotic neuroectodermal tumor of infancy: a proposal for treatment protocol with surgery and adjuvant chemotherapy

The case of a 4-month-old male infant treated with combined surgery and chemotherapy for an aggressive recurrent melanotic neuroectodermal tumor of infancy (MNTI) on the top of the alveolar process of the mandible with a long-term follow-up is presented. Initial treatment comprised conservative local excision and curettage of the mandible. After several local recurrences and because radical surgical excision would give gross functional and aesthetic mutilation, finally complete, long-lasting remission was achieved with adjuvant chemotherapy, according to a neuroblastoma protocol (10-year follow-up). The reason for this protocol was because molecular genetic studies of this tumor showed loss of heterozygosity of chromosome 1p and gain of chromosome 7q analogue to neuroblastomas. A combination of surgery and chemotherapy should be the preferred treatment in case of a recurrence MNTI because optimal functional and aesthetic outcome.

Melanotic neuroectodermal tumor of infancy in the femur: a case report and review of the literature

Melanotic neuroectodermal tumor of infancy (MNTI) is an uncommon neoplasm that most often affects the maxilla in the first year of life. MNTI occurring in the long bones is extremely rare, with only 2 cases reported in the medical literature. Here we report a case of MNTI in the right femur of a 5-month-old infant who underwent neoadjuvant chemotherapy followed by limb-salvage surgery.

Melanotic neuroectodermal tumor of infancy of the femur

Melanotic neuroectodermal tumor of infancy (MNTI) is a rare neoplasm that often occurs during the first year of life. More than 90% of MNTIs occur in the head and neck region, with most on the anterior part of the maxillary ridge. MNTI has also been reported in the mediastinum, thigh, foot, shoulder, and gonads. Here the authors report a rare case of MNTI of the femur in a 3-month-old child.

Melanotic neuroectodermal tumor of infancy: systematic review of the literature and presentation of a case

Melanotic neuroectodermal tumor of infancy (MNTI) is a rare, distinctive neoplasm of early infancy with rapid expansile growth and a high rate of recurrences. Most commonly the lesion affects the maxilla of infants during the first year of life, but it may also occur in the mandible, skull, brain, epididymis, and other rare locations. The origin of the tumor is the neural crest. The expansive, destructive, and rapid growth of MNTI and its effects on the surrounding tissues are the most obvious clinical features. Microscopically, large polygonal epithelioid cells resembling melanocytes, with variable deposits of melanin, and smaller neuroblast-like round cells characterize MNTI. Malignant transformation may occur. Since the first description in 1918, only 215 cases were reported up to the last extensive review in 1992. The present review supplements another 140 published cases of MNTI up to 2004, including an original case report. Clinical features, treatment alternatives, and follow-up are discussed.

Melanotic neuroectodermal tumor of infancy: clinical, radiological, and pathological features

We present a case of a 4-month-old female infant with a maxillary melanotic neuroectodermal tumor of infancy (MNTI) and review the pooled data from previous publications on this entity. The literature to date comprises 378 reported cases from 1918 to the present, from which data on the presence or absence of metastatic disease was available in 311, and on the presence or absence of local recurrence in 165. These pooled data suggest a local recurrence rate of 36% with metastasis occurring in 7% of cases. At present, the optimal management includes complete surgical excision with clear margins, but there are no reliable histopathological or molecular features to predict the biological behavior in individual cases.

Establishment and characterization of new cell lines derived from melanotic neuroectodermal tumor of infancy arising in the mandible

Three cell systems (MINT1/2/3) derived from a melanotic neuroectodermal tumor of infancy (MNTI) arising in the mandible of a 1-month-old newborn boy have been established, and their cytological natures have been characterized. The cells had immunopositivities for pan-keratin, vimentin, neuron-specific enolase, S-100 protein and melanoma-associated antigen (HMB-45). These immunohistochemical phenotypes were basically the same as those observed in tissue sections, in which, synaptophysin, myelin basic protein, c-myc gene products, carcinoembryonic antigen, and epithelial membrane antigen were also immunolocalized in tumor cells. Karyotyping analyzes revealed that the chromosome numbers of the three cell systems ranged from 60 to 67 with 3n ploidies, and that there were many structural aberrations, such as del(11)(q13), del(22)(q13), add(2)(p11), add(7)(q22), extra copies for chromosomes 1, 2, 3, 5, 7, 9, 10, 11, 12, 16, 20, and 22, der(9)t(9;13)(p13;q12)add(9)(q34), and der(13;21)(q10;q10), which were shared by the three cell systems, while der(19)t(11;19)(q13;p13) was found in MINT1 and MINT3. When stimulated by endothelin-3 and vitamin D(3), the cells had spinous cell shapes with immunopositivities for HMB-45, neurofilament protein and glial fibrillary acidic protein, which indicated more neural differentiation. The established cell systems will be useful for further investigation on the molecular and genetic basis of MNTI to understand its pathogenesis, which is largely unknown.

Management of melanotic neuroectodermal tumor of infancy

Melanotic neuroectodermal tumor of infancy is a rare congenital neoplasm involving the head and neck in young patients. The clinical assessment, histologic diagnosis, and management is reviewed, with an emphasis on different treatment alternatives in two new case reports.