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

Melanotic neuroectodermal tumor of infancy: a case report

BACKGROUND

Melanotic neuroectodermal tumor of infancy (MNTI) is a rare clinically benign, pigmented, tumor of neural crest origin which commonly occurs in the maxilla. It is a rare tumor that may pose difficulty in differentiating from other malignant round cell tumors.

CASE PRESENTATION

A 5-month-old Ethiopian infant presented with a mass on his forehead. A wide excision of the lesion was done and subjected to histopathologic evaluation. The histologic and immunohistochemistry for synaptophysin studies confirmed that the infant was having MNTI. The patient was followed and there was no sign of recurrence at the 6th and 9th months of follow-up.

CONCLUSION

MNTI should be considered as a differential diagnosis for tumors occurring in the head region in infants and prolonged follow-up may be needed to check for possible recurrence of the tumor.

A case report of melanotic neuroectodermal tumor of infancy complicated with congenital heart disease and hypothyroidism

To the best of our knowledge, thus far there are no reported cases of melanotic neuroectodermal tumor of infancy (MNTI) with multiple complications. In this case report, we describe the clinical phenotype of MNTI in a 9-month-old female infant associated with tetralogy of Fallot (TOF), a congenital heart defect, and congenital hypothyroidism (CH). Our study showed that the growth of MNTI was delayed by a lower dosage of levothyroxine (L-T4) that was prescribed to treat CH because of the presence of TOF, a severe congenital heart disease. However, the standardized dosage of L-T4 improved thyroid function but stimulated the rapid growth of MNTI. Our report demonstrated that treatment with L-T4 affects the progression of MNTI. Our findings demonstrated the role of thyroid hormone in MNTI growth and progression. Furthermore, our study suggested that the treatment of co-morbidities in children with MNTI requires careful consideration of their effects on the growth and progression of MNTI.

Melanotic neuroectodermal tumor of infancy to the skull: case-based review

BACKGROUND

Melanotic neuroectodermal tumor of infancy (MNTI) is a rare tumor, which usually occurs in infants under the age of one. Early diagnosis and radical surgery seem to be critical for long-term cure.

CASE PRESENTATION

We describe a case of a 4-month-old boy with a MNTI to the skull. The mass was first noticed at 4 month of age and grew very rapidly over a time of 2 weeks. Initially, a fine needle biopsy ruled out a sarcoma and led to the diagnosis. The tumor originated from the sphenoid wing and infiltrated the frontotemporal bone, the lateral wall of the right orbit, and the underlying dura mater. A total excision of the tumor, including the adjacent bone and dura, was achieved. Reconstruction of the bone was performed using absorbable plates and Tutobone. Histology confirmed the initial diagnosis, while molecular diagnosis showed high conformity of the MNTI with medulloblastoma group 3. The patient recovered well, while the reconstruction led to a good cosmetic result. A local recurrence occurred leading to a single-dose chemotherapy with Vincristine and a second surgery after 15 weeks. Thereafter, the patient developed recurrent large pseudomeningocele, which was treated by multiple shunt procedures and finally reconstruction of the bone using Palacos. Radiological follow-up 3 months after the second resection showed no tumor recurrence.

CONCLUSION

Radical surgery for MNTI is to date the gold standard since it seems to minimize recurrence rates. Because of the rapid and destructive growth within the bone, reconstruction is necessary, which can be very challenging in infants.

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.

Prenatal Diagnosis of a Melanotic Neuroectodermal Tumor of Infancy (MNTI): A Case Report With a Favorable Outcome After Chemotherapy Failure and Incomplete Resection

We present the case of a woman referred to our department at 34 weeks of pregnancy with a fetal ultrasonographic scan showing a mass that had developed within the right maxilla with invasion of the orbit. A retrospective examination showed that this tumor had been present since the 12th week of pregnancy. At 39+4 weeks of gestation, a boy was born. He presented a black firm aspect in the maxilla. A computed tomographic scan and magnetic resonance imaging revealed a soft tissue swelling over the right maxilla, extending into the orbit but without invasion of the globe. Surgical biopsy confirmed a melanotic neuroectodermal tumor of infancy. The pathologic examination did not show any neuroblast-like component on the hematoxylin eosin saffron staining. Because of the extension and the size of the lesion, neoadjuvant chemotherapy was carried out. At day 21, the patient received 1 cycle of low-dose cyclophosphamide and vincristine, 2 cycles of etoposide and carboplatin, and thereafter 1 cycle of cyclophosphamide, adriamycin, and vincristin because the lesion kept growing. After stabilization of the size of the tumor, at 4 months, a maxillectomy and partial resection of the orbital floor and lateral orbital wall was performed on the patient. As a complete resection would have required orbital exenteration, surgery was performed deliberately incomplete leaving a macroscopic residue (R2). At 2.5 years of follow-up, the patient showed complete remission with no lesions evident on magnetic resonance imaging.

Melanotic neuroectodermal tumor of infancy (MNTI) of the head and neck: A French multicenter study

OBJECTIVES

Melanotic neuroectodermal tumor of infancy (MNTI) of the head and neck is a rare entity with uncertain clinical behavior. Radical surgical resection is the current recommended treatment, however this can cause severe aesthetic and functional sequelae. The aim of this study was to clinically characterize MNTIs and to stratify risk factors that may influence locoregional recurrence.

METHODS

A retrospective multicenter study, including 11 patients from eight centers with a confirmed diagnosis of MNTI, was conducted. Epidemiological, clinical, radiological, pathological, and immunohistochemical examinations were reviewed. A statistical analysis using a t-test was conducted to calculate parameters correlating with tumor recurrence.

RESULTS

MNTIs mainly occurred in the maxilla, with a mean age at diagnosis of 3.18 months (range: 0-6 months). Primary surgery was performed on 10 patients, with a clear margin resection on two patients. Overall recurrence rate was 27% with a survival of 100% at time of follow-up. No statistical correlation between recurrence rate, age at diagnosis, localization, resection margins, and pathological and immunohistochemical characteristics could be established.

CONCLUSION

In our study, locoregional tumor recurrence did not seem to correlate with resection margins, so a conservative surgical approach may need to be considered to avoid functional and aesthetic sequelae.

Giant melanotic neuroectodermal tumor of infancy (melanotic progonoma) of the head and neck: report of a malignant case

Melanotic neuroectodermal tumor of infancy is a rare congenital pigmented neoplasm of neural crest origin, locally aggressive, growing rapidly and developing during the 1st year of life. It most commonly arises from the maxilla, cranial vault, and mandible. Occasionally, it exhibits malignant behavior with local lymph nodes involvement. Cases misdiagnosed and left untreated for a long time can present challenges due to the tumor mass and infiltration. In these cases, adjuvant chemotherapy can be extremely helpful before radical excision. Authors of this report describe a 4-year-old boy from a developing country who was referred to their hospital with an ulcerated bulging lesion in the midline/right parietooccipital region, extending to the right laterocervical and parotid regions, resulting in significant craniofacial deformation. Magnetic resonance imaging of the brain revealed a highly enhancing tumor with intracranial and extracranial development extending mainly at the level of the right parietooccipital region, with lytic and hypertrophic alterations of the skull. The patient was managed with neoadjuvant and adjuvant chemotherapy and radically resective surgery on metastatic lymph nodes and the primary tumor of the skull. Scheduled radiotherapy was not performed, according to the parents' wishes. The patient returned to his native country where the lesion recurred, and he ultimately died approximately 10 months after the end of the treatment. The literature indicates that tumor removal alone has been the treatment of choice in most isolated cases, but in cases of highly advanced tumor with involvement of the skull and cervical lymph nodes, it is preferable to proceed with preoperative chemotherapy with the aim of reducing the tumor volume, allowing better technical conditions for complete surgical removal, and decreasing the risk of local recurrence or metastasis.