Melanotic neuroectodermal tumour of infancy (MNTI). Immunohistochemical and ultrastructural study of a case

Melanotic neuroectodermal tumor of infancy of maxilla: Report of a case with review of literature

Melanotic neuroectodermal tumor of infancy (MNTI) is a rare, fast-growing, pigmented neoplasm of neural crest origin. Despite of its rapid and locally infiltrative growth, it is still considered benign with high recurrence rate and malignant potential, so early diagnosis is extremely important to limit its local expansion. Recurrences can be expected primarily because of incomplete excision, tumor dissemination, or due to its multicentric nature. We report a case of MNTI originating in the maxilla of a 7-month-old male infant, which was managed with complete surgical excision of the tumor, with no signs of recurrence after a 1-year follow-up period. In addition, a complete literature review has been reported, in an attempt to understand the origin, histopathologic and immunohistochemistry features with surgical modalities and advantages of radiotherapy and chemotherapy in cases where complete surgical extirpation is questionable.

Melanotic neuroectodermal tumour of infancy - A rare entity

Melanotic neuroectodermal tumour of infancy (MNTI) is rare, rapidly growing, pigmented neoplasm of neural crest origin. It is generally accepted as a benign tumour despite of its rapid and locally destructive growth. It primarily affects the maxilla of infants during the first year of life. Surgical excision is considered as the treatment of choice. The recurrence rate varies between 10% and 15%, and malignant behaviour has been reported in 6.5% of cases. We report a case of MNTI, associated with an erupted primary tooth in a 5-month-old male child. We discuss the clinical, radiographic and histologic features of this rare tumour, as well as its surgical management and the follow-up.

Mandibular melanotic neuroectodermal tumor of infancy: a role for neoadjuvant chemotherapy

Melanotic Neuroectodermal Tumor of Infancy (MNTI) is a rare, locally aggressive neoplasm with a predilection for the head and neck area, most commonly occurring in the maxilla. The vast majority of treatment modalities for all cases of MNTI to date have involved surgical intervention only, with just 9.6 % involving some sort of chemotherapy, radiotherapy, or a combination of the prior mentioned modalities. There is very limited information available regarding the use of neoadjuvant chemotherapy, due to its rare nature. In this report, a 4 month old girl presented to our clinic with a chief complaint of a large oral mass of about 2.5 months in duration. Intraoral examination showed an oral mass arising from the lingual aspect of inferior alveolar ridge with extensive mandibular invasion. The patient received three cycles of vincristine, Adriamycin, and cyclophosphamide as neodajuvant therapy. Upon completion, the tumor had decreased significantly in size. The patient was then scheduled for surgery and underwent surgical resection of the tumor. We were able to obtain adequate shrinkage of the tumor to allow better resectability, easier surgical access and a more minimally invasive approach with no lip split and a smaller neck incision. In conclusion, we have reported an extremely rare case of MNTI of the mandible that was successfully treated with neoadjuvant chemotherapy and surgical resection. This approach was advantageous to minimize the chance of recurrence and improve resectability in particularly large tumors, while maximizing functional outcomes and minimizing deformity.

Melanotic neuroectodermal tumor of infancy in thigh of an infant--a rare case report with diagnostic implications

Melanotic neuroectodermal tumor of infancy (MNTI) is an uncommon tumor of neural crest origin, almost invariably identified in the head and neck region. It is a relatively benign tumor but can recur and rarely metastasize. Herein, a rare case of MNTI in the thigh of an infant is documented. Radiographic imaging showed a sclerotic and lytic lesion in the metadiaphyseal region of the right femur with a soft tissue component. The clinicoradiological impression was of a malignant round cell tumor and osteomyelitis. The patient's urinary vanil mandelic acid (VMA) level was elevated. FNAC smears revealed a tumor with round to polygonal cells, focally containing black melanin pigment. Biopsy and tumor excision revealed a tumor with cells in cords and nests embedded in a fibrocollagenous stroma and showed bone and soft tissue infiltration. On immunohistochemistry, tumor cells displayed immunoreactivity to vimentin, cytokeratin (CK), CK7, CK19, and MIC2, and focal reactivity for synaptophysin and HMB45. Diagnosis of an MNTI was made. The patient underwent induction chemotherapy with extracorporeal radiotherapy, followed by a soft tissue excision that revealed residual tumor. Surgically, free marrow margins were accomplished, and the patient is currently being followed-up. To the best of our knowledge this case is the fifth documented case in the English literature of MNTI in the thigh. The diagnostic and therapeutic implications are discussed.

Melanotic neuroectodermal tumour of infancy

Melanotic neuroectodermal tumour of infancy (MNTI) is a rare benign tumour of neural crest origin that was first described by Krompecher in 1918.1 It is predominantly found in infancy, with about 92% of cases below the age of 12 months and 82% below the age of 6 months. The predominant site of origin is in the premaxilla though it is reported at other sites also including the skull, the mandible, the epididymis and the brain.2 The lesions often have areas of bluish discolouration on the surface and are characterised by displacement of the involved tooth bud and local aggressiveness. The present report deals with two cases of MNTI, a 5-month-old baby girl and a 6-month-old baby boy who reported to the Department of Oral and Maxillofacial Pathology, Dr R Ahmed Dental College and Hospital, Kolkata, India. The clinical, radiological, histological and immunohistochemical findings, confirmed the diagnosis of MNTI. Flow cytometry was performed to analyse aneuploidy. The tumours were treated surgically with no history of recurrence to date.

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.

Stephen L. Gans Distinguished Overseas Lecture. The neural crest in pediatric surgery

AIM

This review highlights the relevance of the neural crest (NC) as a developmental control mechanism involved in several pediatric surgical conditions and the investigative interest of following some of its known signaling pathways.

METHODS

The participation of the NC in facial clefts, ear defects, branchial fistulae and cysts, heart outflow tract and aortic arch anomalies, pigmentary disorders, abnormal enteric innervation, neural tumors, hemangiomas, and vascular anomalies is briefly reviewed. Then, the literature on clinical and experimental esophageal atresia-tracheoesophageal fistula (EA-TEF) and congenital diaphragmatic hernia (CDH) is reviewed for the presence of associated NC defects. Finally, some of the molecular signaling pathways involved in both conditions (sonic hedgehog, Hox genes, and retinoids) are summarized.

RESULTS

The association of facial, cardiovascular, thymic, parathyroid, and C-cell defects together with anomalies of extrinsic and intrinsic esophageal innervation in babies and/or animals with both EA-TEF and CDH strongly supports the hypothesis that NC is involved in the pathogenesis of these malformative clusters. On the other hand, both EA-TEF and CDH are observed in mice mutant for genes involved in the previously mentioned signaling pathways.

CONCLUSIONS

The investigation of NC-related molecular pathogenic pathways involved in malformative associations like EA-TEF and CDH that are induced by chromosomal anomalies, chemical teratogens, and engineered mutations is a promising way of clarifying why and how some pediatric surgical conditions occur. Pediatric surgeons should be actively involved in these investigations.

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 tumour of infancy arising in the maxilla

Melanotic neuroectodermal tumour of infancy is an uncommon neoplasm that usually occurs in children aged one year or less. Difficulty in deciding the cellular origin of this tumour has led to numerous names, including congenital melanocarcinoma, melanotic epithelial odontoma, melanotic ameloblastoma, and retinal anlage tumour. Electron microscopy and histochemical studies, however, have now established the neural crest origin. The most frequent site of occurrence is the maxilla followed by the skull, the brain and the mandible. The genital organs are the most frequent extracranial site. We present two cases of melanotic neuroectodermal tumour of infancy arising in the maxilla.

Melanotic neuroectodermal tumour of infancy: an immunohistochemical and ultrastructural study

Two cases of melanotic neuro-ectodermal tumour of infancy (MNTI)--a rare neoplasm arising in the first year of life--are reported, with the results of immunohistochemical and ultrastructural examination. The tumours consisted of a biphasic cell population in a fibrous stroma. The small, darkly staining cells comprising the first population stained positively for synaptophysin, showing them to be neuroblasts, and the large epithelioid cells comprising the second cell population stained positively with the antibodies HMB-45 and NKI-Beteb, showing them to be melanocytes. Ultrastructural examination of the second case confirmed the biphasic nature of the tumour cells, with secretory granules and neurofilaments in the neuroblastic population, and melanosomes in the epithelioid population. These results add to the evidence supporting the neural crest origin of MNTI and confirm its formation from two distinct cell lines. Both cases have responded to local excision, with no recurrence more than a year after initial treatment.

Melanotic neuroectodermal tumour of infancy: a case report emphasizing the importance of computed tomography

A case is reported of the rare melanotic neuroectodermal tumour of infancy involving the maxilla of a 4-month-old girl. The role of CT is discussed with particular reference to the diagnosis.

Maxillectomy in childhood

A maxillectomy in the upper part of the maxilla is an uncommon operation in childhood. The authors comment on the clinical evolution, the related pathologies and the surgical techniques employed in the treatment of eight patients.