The Role of Chemotherapy in Management of Inoperable, Metastatic and/or Recurrent Melanotic Neuroectodermal Tumor of Infancy-Own Experience and Systematic Review

Simple Summary

Melanotic Neuroectodermal Tumor of Infancy (MNTI) is a very rare neoplasm that most commonly develops within maxilla in infants. It usually has a benign clinical course and is treated with only surgery. However, patients with large, inoperable, metastatic or multiply recurring MNTI may require systemic treatment. The role of pre- and post-surgery chemotherapy (CHT) in the management of MNTI is unclear. Here, we have presented the disease courses and outcomes of four infants treated with multidrug CHT due to inoperable/recurrent MNTI. Additionally, a systematic literature review was performed which revealed 38 similar cases in the last 42 years. Most children with primarily inoperable MNTI responded to CHT, which allowed physicians to perform complete, non-mutilating delayed surgery. However, it is still uncertain whether CHT administered after incomplete resection of MNTI prevents recurrence. This study aimed to contribute to the establishment of standards of management in patients with inoperable, metastatic or persistently recurring MNTIs, which are currently lacking.

Abstract

Melanotic Neuroectodermal Tumor of Infancy (MNTI) is a very rare pediatric neoplasm of neural crest origin. In most cases, it develops in infants as a localized tumor of the maxilla, and surgery is usually curative. In less than 10% of patients with inoperable, metastatic or persistently recurring MNTI, chemotherapy (CHT) may be considered; however, its role is still unclear. The aim of our study was to assess the efficacy of CHT in children with large, inoperable, metastatic and/or recurrent MNTI. Four such infants, treated with CHT in Polish and German centers of pediatric oncology, were presented. Additionally, a systematic literature search of the PubMed/MEDLINE, Scopus and Web of Science databases was performed, yielding 38 similar cases within the last 42 years. Neoadjuvant CHT, based mainly on the protocols for neuroblastoma, was often effective, allowing for complete delayed surgery in most cases. However, the role of adjuvant CHT in preventing recurrences after incomplete resection of MNTI remains unclear. Disseminated inoperable MNTI was almost universally associated with poor response to CHT and unfavorable outcome. Further investigations to elaborate standards of management in patients with inoperable, metastatic or persistently recurring MNTIs are necessary to improve outcomes.

Pigmented lesions in unusual anatomic sites

This review considers pigmented melanin-containing lesions arising in extracutaneous locations. It includes reactive lesions as well as benign and malignant neoplasms. Melanocytic lesions of the mucosae, nervous system, and individual organs are discussed, and rarer pigmented tumors in unusual sites are also covered. A brief description of the histology and clinical behavior along with proposed explanations for their ectopic location are provided. Emphasis is given to the reality that detailed morphological evaluation and application of ancillary techniques can establish the melanocytic nature and biologic potential of such tumors, but cannot, by themselves, determine the primary or metastatic nature of these lesions.

Mesenchymal tumors and tumor-like lesions of the female genital tract: a selective review with emphasis on recently described entities

The diverse mesenchymal tumors and tumor-like lesions that occur within the female genital tract include a number of lesions that have only been recently characterized and others about which there is new information. In this group are the aggressive angiomyxoma, angiomyofibroblastoma, and cellular angiofibroma. Criteria for the distinction of these lesions are reviewed, as are the pathologic features of prognostic significance in assessing smooth muscle tumors of the vulva. The diagnostic problems that the epithelioid variant of smooth muscle tumors, both benign and malignant, may pose when they occur in various areas of the genital tract are discussed, particularly with regard to problems encountered in the ovary, a site where the diagnosis often is not considered. Recent information expanding the morphologic spectrum of fibroepithelial polyps of the genital tract is presented, and important non-neoplastic entities, including nodular fasciitis and the postoperative spindle cell nodule, are reviewed. Mesenchymal tumors of the various types seen in the soft tissues may be encountered anywhere in the female genital tract and have been the subject of particular recent interest in the ovary; issues relevant to differential diagnosis are reviewed.

Endometrial endometrioid carcinomas associated with Ewing sarcoma/peripheral primitive neuroectodermal tumor

Three uterine tumors, each consisting of endometrioid carcinoma and Ewing's sarcoma/peripheral primitive neuroectodermal tumor (ES/pPNET) are described. The diagnosis of ES/pPNET in each case was first established in the hysterectomy specimen because each ES/pPNET was misinterpreted on the endometrial biopsy specimens as a high-grade homologous sarcoma. The ES/pPNET element in each case consisted of solid masses of small- to medium-sized round cells without Homer-Wright pseudorosettes, glial or ganglion cells, true rosettes with central lumens, or medulloepithelial tubules. Each ES/pPNET exhibited focal positive immunostaining for neuron-specific enolase, diffuse staining for vimentin, and strong cell membrane immunoreactivity for O13 (CD99), the last finding providing the first clue to the diagnosis of ES/pPNET in each case. The diagnosis in each case was confirmed by detection of EWS/FLI-1 fusion transcript through reverse transcription polymerase chain reaction. We also examined O13 immunoreactivity retrospectively in 40 cases of malignant mixed mullerian tumors (MMMT) with homologous or heterologous elements. O13 immunoreactivity was not observed in the malignant epithelium or in the homologous or heterologous sarcomas. The immunoreactivity of O13 in round cell endometrial sarcomas provides a clue to the diagnosis of ES/pPNET.

Fine needle aspiration in the pre-operative diagnosis of melanotic neuroectodermal tumour of infancy

A case of melanotic neuroectodermal tumour of infancy is described. The pre-operative diagnosis was made on cytological material obtained by fine needle aspiration. The patient was a three-month-old male infant with a rapidly growing maxillary tumour mass that also involved the pterygomaxillary fossae and the floor of the orbit. In addition to the typical clinical presentation, the cytology is also distinctive showing a dual population of small neuroblastic cells and large melanin-containing epithelial cells. Histological, immunohistochemical and electron microscopic examination of the excised mass confirmed the initial diagnosis. The pre-operative distinction of this tumour from other small round cell tumours of infancy (rhabdomyosarcoma, neuroblastoma, melanoma and lymphoma), is essential in order to plan the most complete resection therefore reducing the possibilities of tumour recurrence. This tumour belongs to a field of pathology with which many otolaryngologists may not be familiar.