Computed tomographic imaging features of maxillary and mandibular melanotic neuroectodermal tumor of infancy: Report of 2 cases and systematic review.

OBJECTIVE: The aim of this systematic review was to determine the computed tomographic (CT) imaging characteristics of maxillary and mandibular melanotic neuroectodermal tumor of infancy (MNTI). Two cases from our institution were also presented. STUDY DESIGN: Full-text case reports and case series of histopathologically proven gnathic MNTI with CT figures of diagnostic quality were searched in PubMed, Scopus, Web of Science, Ovid, and Google Scholar databases from July 2021 to February 2022. Descriptive statistics were used to determine the frequency of each CT feature of gnathic MNTI. RESULTS: Fifty-two published studies met the eligibility criteria, providing a total of 53 maxillary and mandibular MNTIs for analysis. In order of frequency, the CT features of gnathic MNTI that were present in over half of the study sample were bone expansion (53, 100%), a well-defined periphery (49, 92.5%), tooth displacement (45, 84.9%), and a bilocular radiolucent internal pattern (32, 60.4%). CONCLUSIONS: The bilocular radiolucent internal pattern has not been recognized as a common CT feature of gnathic MNTI. When associated with a well-defined, expansile mass in the infantile maxilla or mandible, this imaging characteristic can support a radiologic interpretation of MNTI.

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.

[Orbital melanotic neuroectodermal tumor in an infant].

A 3-month-old infant patient presented with a 1-week history of a quickly progressive mass in the left eye. A hard, irregularly shaped tumor was found in the superolateral orbit. B-scan showed an uneven hypoecho and an undefined lesion. On the orbital CT, a soft tissue mass was located around the left zygomatic tubercle, involving part of the bone and lacrimal gland. The left orbital mass was removed under general anesthesia after admission. The histological and immunohistochemical examination revealed it was a melanotic neuroectodermal tumor. The infant patient was followed up for 6 months after the operation, and no recurrence was found. (Chin J Ophthalmol, 2021, 57: 372-374).

Melanotic Neuroectodermal Tumor of Infancy at Skull: Rare and Rapid-Growing Tumor but Histologically Benign.

INTRODUCTION: Melanotic neuroectodermal tumor of infancy (MNTI) is a rare and rapid-growing tumor. However, a neurosurgeon should not overlook this entity when differential diagnosing rapid-growing skull tumor because its histology nature is just benign, and the prognosis is much better than other malignant tumors. CASE PRESENTATION: We reported the case of a 5-month old male presenting with progressive rapid-growing skull tumor which became 10 cm in diameter in only 5 months compared to the normal head circumference at birth. At first, we thought of malignant skull tumor and performed only biopsy to establish diagnosis. But, when the pathology revealed benign MNTI, we performed preoperative tumor embolization and then radical surgery. Good result was observed. DISCUSSION: Skull MNTI is the second most common location after the maxilla. Even advanced imaging nowadays cannot distinguish MNTI from other malignant tumors definitely. Urgent biopsy is recommended to establish diagnosis of this benign tumor first. Preoperative angiography with tumor embolization is recommended when feasible, followed by craniotomy with radical resection.

Melanotic Neuroectodermal Tumor of Infancy in the Ulna of an Infant: A Very Rare Tumor: A Case Report.

CASE: A 4-month-old boy presented with a nontender swelling of the right proximal forearm of 2 months' duration. Radiological evaluation showed lytic lesion surrounded by sclerotic bone in the ulna with soft-tissue extension. Histopathological examination showed tumor of round and epithelioid cells containing melanin, interpreted as melanotic neuroectodermal tumor. The patient underwent a wide excision of the shaft of the ulna with creation of radioulnar synostosis. There is no recurrence 6 years after surgery. CONCLUSION: Melanotic neuroectodermal tumor is rare in the appendicular skeleton and has to be differentiated from other round cell tumors and osteomyelitis. As far as we know, this is the first reported case in the ulna.

Melanotic neuroectodermal tumor of infancy successfully treated with metformin: A case report.

RATIONALE: Melanotic neuroectodermal tumor of infancy (MNTI) is a rare tumor originated from neural crest cells with the potential for recurrence and metastasis. The peak age for the disease is during the first year after birth. The current therapy is primarily surgery. The patient reported here is the first case of MNTI treated with metformin. PATIENT CONCERNS: A case of a 4-month-old infant with a history of swelling in the mouth for 1 month. DIAGNOSIS: The tumor was diagnosed using radiology, pathology, and immunohistochemistry, and it was performed with complete surgical resection. Unfortunately, the tumor recurred 3 months after surgery. INTERVENTIONS: We prescribed metformin for the infant. OUTCOMES: Currently, after 9 months of treatment, the tumor is well controlled without apparent side effects. LESSONS: The case presented suggested that metformin may be an underlying therapy for MNTI.

Oral melanotic neuroectodermal tumor of infancy: Management of a case affecting the maxilla.

Melanotic neuroectodermal tumor is a rare benign congenital neoplasm involving the head-and-neck region found in infants <1 year of age. The lesion most commonly affects the maxilla. We report the case of a 4-month-old male child with a tumor involving the anterior region of the maxilla along with a brief review of literature, differential diagnosis, and treatment.

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.

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.

Epididymal melanotic neuroectodermal tumor of infancy: A rare cause of scrotal mass in an infant.

Melanotic neuroectodermal tumor of infancy (MNTI) is a rare, benign neoplasm of neural crest origin more commonly seen in the craniofacial region. We report a case of MNTI of the epididymis in a 6-month-old male child with emphasis on the sonographic appearance which has not been previously described. In this case, the mass was inseparable from the testicle and therefore the differential diagnosis considered both extratesticular and intratesticular masses. MNTI should be added to the differential diagnosis of scrotal masses, particularly if they present in a child younger than 12 months of age.

Use of Technological Aids in the Resection of a Rare Maxillofacial Tumor of Infancy.

Melanotic neuroectodermal tumor of infancy is a rare maxillofacial tumor, usually presenting within the first year of life, often a benign locally aggressive lesion, with wide local excision providing the best opportunity of cure. In past reports, direct tissue visualization guided resection, with occasional need for reoperation to clear margins. In this case report, a method is presented to achieve clear margins in surgery using virtual surgical planning and surgical stealth navigation.

Difficult Nasal Intubation Using Airway Scope® for a Child With Large Tumor.

We report a case of difficult nasal intubation utilizing a Pentax-Airway scope® AWS-100. A 4-month-old female with a rapidly growing melanotic neuroectodermal tumor was scheduled for resection under general anesthesia. The tumor was a large rubbery mass located in the middle of the mandible. For nasal intubation using the AWS, guidance of the tube toward the glottis was attempted using pediatric Magill forceps. Although we could hold the tube with the Magill forceps, it was difficult to insert the tube into the trachea due to the limited space in her hypopharynx. We then used a standard laryngoscope with a Miller straight blade for direct visual laryngoscopy and successfully intubated the patient with the aid of the pediatric Magill forceps. We often experience difficulty navigating a nasal endotracheal tube toward the glottis even when a clear glottic view is obtained with video laryngoscopes, especially in children with a small oropharyngeal space. However, some reports have been shown that video laryngoscopes are useful for intubation of the difficult airway and causes less stress to the upper airway than direct visual laryngoscopy. Video laryngoscopy can be an excellent way to provide nasal intubation in some but not all children.

Melanotic neuroectodermal tumour of infancy: A case report and differential diagnosis.

Melanotic neuroectodermal tumour of infancy is an uncommon pigmented neoplasm of neural crest origin. It was first described in 1918 by Krompecher, known as congenital melanocarcinoma at that time. Although it is generally agreed upon that it is a benign entity, it is locally aggressive and has a significant recurrent risk, reported to be between 10-15%. There have also been prior reports of malignant behaviour in these tumours, although extremely rare. The majority of cases of this tumour (about 70%) arise from the maxilla and its occurrence in the cranial vault represents approximately 15.6% of cases. We describe a rare case of melanotic neuroectodermal tumour of infancy, with simultaneous involvement of the cranial vault and petrous temporal bone, in a four-month-old child, complicated by post-surgical pseudo-meningocele. This case illustrates the diagnostic dilemma in differentiating reactive osseous sclerosis from direct tumour infiltration, both of which can occur in the context of melanotic neuroectodermal tumour of infancy. The discussion places emphasis on differential diagnoses and useful radiological features to assist in clinching the diagnosis of melanotic neuroectodermal tumour of infancy.

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 with Involvement of the Superior Sagittal Sinus.

Melanotic neuroectodermal tumor of infancy (MNTI) is a rare lesion that typically manifests in the first year of life, most commonly involving the facial bones. We present 2 infants with MNTI involving the posterior skull with associated compression of the superior sagittal sinus (SSS). A review of the anatomical locations of MNTI is offered, and the implications of SSS involvement are described. This represents the first known description of MNTI with involvement of the posterior SSS.

Melanotic neuroectodermal tumor of infancy.

Melanotic neuroectodermal tumor of infancy (MNTI) is a rare pigmented craniofacial tumor of newborns and infants. We report the imaging findings of a 3-month old male patient with a maxillary MNTI. Detailed discussion on imaging features on various magnetic resonance sequences and CT scan are included. Characteristic radiographic appearance is also described. MNTI, of neural crest origin, display a biphasic population of melanin containing cells and neuroblastic cells, within a moderately vascularized fibrous stroma. The child underwent complete surgical excision with no evidence of recurrence at one year follow up. MNTI is an unusual tumor occurring in early childhood with a predilection for the maxilla. Clinical findings, CT scan and MRI may allow a preoperative diagnosis.

Clinicopathological features of melanotic neuroectodermal tumor of infancy: Report of two cases.

Melanotic neuroectodermal tumor of infancy (MNTI) is an extremely rare, pigmented neoplastic entity of neural crest origin. Histological and immunohistochemical profiles indicate the presence of two components, small rounded neuroblast-like cellular areas and areas with large melanin-containing cells which consist of combination of neural, melanocytic, and epithelial cell types. Here we present two interesting cases of infants with MNTI which have different clinicopathological features. The first case is a 3-month-old female with rapidly growing MNTI involving the lacrimal sac and inferior wall of the orbital cavity, treated with total maxillectomy without orbital exenteration followed by chemotherapy. The second case is a 7-month-old male with slow-growing maxillary MNTI treated with complete surgical excision. In the female patient, histological findings revealed a predominance of neuroblast-like cellular areas and a high Ki67 index indicating rapid cellular proliferation. In the male patient however, large melanin-containing cells were dominant in this slow-growing tumor. These findings support the presence of two different types of MNTI, rapid-growing and slow-growing types, determined by the component of neuroblast-like cellular areas.

Melanotic Neuroectodermal Tumor of Infancy: A Systematic Review.

Melanotic neuroectodermal tumor of infancy (MNTI) is a rare tumor, usually diagnosed within the first year of age, with a predilection for the maxilla. Although the tumor is usually benign, its rapidly growing nature and ability to cause major deformities in surrounding structures necessitate early diagnosis and intervention. It is important that medical and dental specialists are prepared to make the diagnosis and proceed with appropriate intervention. The authors performed a systematic review of the 472 reported cases from 1918 through 2013 and provided a comprehensive update on this rare entity that can have devastating effects on young patients. This investigation uncovered age at diagnosis as an important prognostic indicator, because younger age correlated with a higher recurrence rate. The authors also present a case report of a 5-month-old girl diagnosed with MNTI and review her clinical presentation and imaging and histopathologic findings.