Melanotic Neuroectodermal Tumor of Infancy: Report of 2 Cases

Melanotic Neuroectodermal Tumor of Infancy: a Clinicopathological Case Report

Melanotic neuroectodermal tumor of infancy (MNTI) is a rare neoplasm that affects mainly children under 1 year of age. A 4-month-old boy was referred for evaluation of a lesion with 1 month of evolution. Intra-oral examination detected a firm upon palpation submucosal nodular mass, measuring 1.5 cm in diameter, affecting the anterior maxillary alveolar ridge and covered by a slightly blue mucosa with evident telangiectasia. The patient underwent an incisional biopsy and histological and immunohistochemical analyses revealed nests of AE1/AE3 positive epithelioid cells with abundant melanin pigmentation. Other cell types, resembling neuroblasts, were also present and positive for CD56, synaptophysin and enolase. The diagnosis of MNTI was established and the patient was referred for treatment. Conservative surgical resection was performed along with 3 adjacent teeth under general anesthesia. The patient is in follow-up for 1,5 year without recurrence. Conservative surgical management of MNTI may be an alternative to maxillectomy, contributing to the patient´s quality of life.

S100B raises the alert in subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) is a devastating disease with high mortality and mobility, the novel therapeutic strategies of which are essentially required. The calcium binding protein S100B has emerged as a brain injury biomarker that is implicated in pathogenic process of SAH. S100B is mainly expressed in astrocytes of the central nervous system and functions through initiating intracellular signaling or via interacting with cell surface receptor, such as the receptor of advanced glycation end products. The biological roles of S100B in neurons have been closely associated with its concentrations, resulting in either neuroprotection or neurotoxicity. The levels of S100B in the blood have been suggested as a biomarker to predict the progress or the prognosis of SAH. The role of S100B in the development of cerebral vasospasm and brain damage may result from the induction of oxidative stress and neuroinflammation after SAH. To get further insight into mechanisms underlying the role of S100B in SAH based on this review might help us to find novel therapeutic targets for SAH.

BRAFV600E Mutation in Melanotic Neuroectodermal Tumor of Infancy: Toward Personalized Medicine?

The melanotic neuroectodermal tumor of infancy (MNTI) is a rare neoplasm that primarily affects the maxilla of infants during their first year of life. Complete resection is the conventional treatment and recurrence rates vary from 10% to 60%. The recurrent tumors grow more aggressively and can invade other anatomic structures, such as the nasal cavity, the orbit, and the skull base. The aggressive behavior of MNTIs may require radical resection, which may not be possible in some cases because of its rapid and invading growth together with invasion of vital structures. In these situations, adjunct radiotherapy or chemotherapy has been used. However, as there are no conclusive data regarding the molecular profile of this tumor, currently there is no targeted therapy that may be used in the treatment of selected aggressive cases. On the basis of MNTI similarities with melanomas, such as derivation from the neural crest cells and presence of large melanin-containing cells, we hypothesized that MNTIs also may harbor the BRAFV600E oncogenic mutation. We show for the first time that this important pediatric tumor may harbor the oncogenic BRAFV600E mutation, providing the first insights to their personalized treatment.

Melanotic neuroectodermal tumor of infancy in an African-indigenous patient from the Amazon: a case report

Melanotic neuroectodermal tumor of infancy (MNTI) is a rare condition that occurs normally in the anterior maxilla of infants aged <1 year. The use of clinical and imaging tools for MNTI is extremely important to prevent problems with function as well as the aesthetic features in a breastfeeding child. Brazil is a multiethnic country with a poor epidemiological policy and little data to track the incidence of certain diseases, including MNTI. It is important to study this pathology with ethnicity as a factor to improve the current epidemiological programs and establish better post-treatment management. This paper describes a case of a 2-month-old male of African-indigenous descent and Brazilian Amazon residency, who presented to our unit in 2009 with a history of an expanding mass involving the anterior maxilla. Clinical and computerized tomography scans were used to diagnose the mass as MNTI, which was removed by total excision. A biopsy later confirmed the MNTI diagnosis.