Pigmented neuroectodermal tumor of infancy in the epididymis. A case report

Melanotic Neuroectodermal Tumor of Infancy Presenting With Fast-Growing Scrotal Swelling: A Case Report and Literature Review

Testicular melanotic neuroectodermal tumor of infancy (MNTI) is extremely rare, with 2 cases reported in the literature. Its rarity and rapid and infiltrative growth pattern pose a diagnostic challenge. A previously healthy 3-month-old male, presented with a history of worsening left hemiscrotal swelling for 1 week. An outside ultrasound was suggestive of testicular torsion. Left orchiectomy demonstrated a mass occupying almost entire testicle with a variegated cut surface, with areas of pigmentation, necrosis, and hemorrhage. Histological examination confirmed MNTI of the testis and epididymis. MNTI should be included in differential diagnosis in infants presenting with fast-growing scrotal swelling.

Melanotic Neuroectodermal Tumor of Infancy in the Epididymis: A Brief Report and Review of the Role of Chemotherapy in Management

Melanotic neuroectodermal tumor of infancy is a rare benign tumor of neural crest origin. The tumor generally presents in the jawbones; however, it occasionally occurs in extracranial sites. Although 95% of these tumors present within the first year of life and 15% in extracranial locations, we report an unusual case of a 15-month-old male with melanotic neuroectodermal tumor of infancy of the epididymis. The patient underwent orchiectomy without adjuvant chemotherapy or radiation. Twenty months later, there was no sign of recurrence. In addition, we discuss the role of chemotherapy and radiation and the potential importance of molecular genetics in establishing guidelines for management.

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

INTRODUCTION

Melanotic neuroectodermal tumor of infancy (MNT1) is a rare congenital pigmented neoplasm of neural crest origin, locally aggressive, and rapidly growing that develops during the first year of life. It most commonly arises from the maxilla, the cranial vault, and the mandible. Early diagnosis and radical surgery are critical for a long-term outcome.

METHODS

A literature search through PUBMED revealed 43 cases of MNT1 arising in the skull. We reviewed the available literature and studied the presenting symptoms, diagnostic procedures, treatment, rates of recurrences, malignancy, and data of follow-up. We report two further cases of infants aged 4 and 10 months, respectively, with MNT1 arising from the cranial vault who underwent radical excision of the lesion.

CONCLUSION

Melanotic neuroectodermal tumor of infancy should be included in the differential diagnosis of skull lesions in infants. Radical surgery must be considered as the treatment of choice and close follow-up for at least 2 years is necessary.

Melanotic neuroectodermal tumor of infancy: systematic review of the literature and presentation of a case

Melanotic neuroectodermal tumor of infancy (MNTI) is a rare, distinctive neoplasm of early infancy with rapid expansile growth and a high rate of recurrences. Most commonly the lesion affects the maxilla of infants during the first year of life, but it may also occur in the mandible, skull, brain, epididymis, and other rare locations. The origin of the tumor is the neural crest. The expansive, destructive, and rapid growth of MNTI and its effects on the surrounding tissues are the most obvious clinical features. Microscopically, large polygonal epithelioid cells resembling melanocytes, with variable deposits of melanin, and smaller neuroblast-like round cells characterize MNTI. Malignant transformation may occur. Since the first description in 1918, only 215 cases were reported up to the last extensive review in 1992. The present review supplements another 140 published cases of MNTI up to 2004, including an original case report. Clinical features, treatment alternatives, and follow-up are discussed.

Melanotic neuroectodermal tumor of infancy: clinical, radiological, and pathological features

We present a case of a 4-month-old female infant with a maxillary melanotic neuroectodermal tumor of infancy (MNTI) and review the pooled data from previous publications on this entity. The literature to date comprises 378 reported cases from 1918 to the present, from which data on the presence or absence of metastatic disease was available in 311, and on the presence or absence of local recurrence in 165. These pooled data suggest a local recurrence rate of 36% with metastasis occurring in 7% of cases. At present, the optimal management includes complete surgical excision with clear margins, but there are no reliable histopathological or molecular features to predict the biological behavior in individual cases.

Establishment and characterization of new cell lines derived from melanotic neuroectodermal tumor of infancy arising in the mandible

Three cell systems (MINT1/2/3) derived from a melanotic neuroectodermal tumor of infancy (MNTI) arising in the mandible of a 1-month-old newborn boy have been established, and their cytological natures have been characterized. The cells had immunopositivities for pan-keratin, vimentin, neuron-specific enolase, S-100 protein and melanoma-associated antigen (HMB-45). These immunohistochemical phenotypes were basically the same as those observed in tissue sections, in which, synaptophysin, myelin basic protein, c-myc gene products, carcinoembryonic antigen, and epithelial membrane antigen were also immunolocalized in tumor cells. Karyotyping analyzes revealed that the chromosome numbers of the three cell systems ranged from 60 to 67 with 3n ploidies, and that there were many structural aberrations, such as del(11)(q13), del(22)(q13), add(2)(p11), add(7)(q22), extra copies for chromosomes 1, 2, 3, 5, 7, 9, 10, 11, 12, 16, 20, and 22, der(9)t(9;13)(p13;q12)add(9)(q34), and der(13;21)(q10;q10), which were shared by the three cell systems, while der(19)t(11;19)(q13;p13) was found in MINT1 and MINT3. When stimulated by endothelin-3 and vitamin D(3), the cells had spinous cell shapes with immunopositivities for HMB-45, neurofilament protein and glial fibrillary acidic protein, which indicated more neural differentiation. The established cell systems will be useful for further investigation on the molecular and genetic basis of MNTI to understand its pathogenesis, which is largely unknown.

Cytologic diagnosis of a melanotic neuroectodermal tumor of infancy occurring in the cranial bones

Melanotic neutroectodermal tumor of infancy (MNTI) is a rare, usually benign tumor commonly occurring in the maxilla. MNTIs at unusual sites like the cranium clinically mimic malignant small round cell tumors. Consequently, a correct preoperative cytologic diagnosis of MNTI at these sites helps in the surgical management of the patient. We report on a cytologically diagnosed case of MNTI in the frontotemporal region of the skull in an infant. Aspirates from the lesion were cellular, with a bimodal population mainly of small neuroblast-like cells admixed with a few large epithelioid cells with melanin granules. In the present case, following the cytologic diagnosis a wide local excision was carried out, and the histologic examination confirmed the cytologic diagnosis. Diagn. Cytopathol. 1999;21:280-283.

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.