Melanotic Neuroectodermal Tumor of Infancy: A Molecular Genetic Study

Abstract

Melanotic neuroectodermal tumor of infancy is a rare but well-recognized entity in pediatric pathology. However, the relationship of this tumor to other pediatric small cell tumors with neuroectodermal features (such as neuroblastoma, Ewing sarcoma/peripheral primitive neuroectodermal tumor, and desmoplastic small round cell tumor) is undetermined. Molecular genetic studies of melanotic neuroectodermal tumor of infancy have not been reported. We studied three typical cases of melanotic neuroectodermal tumor of infancy in an attempt to link this tumor to other small cell tumors with well-characterized molecular genetic changes. Tests performed included: detection of MYCN gene amplification and deletion of 1p (all 3 cases), and presence of the t(11;22)(q24;q12) and the t(11;22)(p13;q12) translocations (2 of 3 cases). None of these tests yielded positive results. Thus, there is no genetic basis at present to link melanotic neuroectodermal tumor of infancy to neuroblastoma, Ewing sarcoma/peripheral primitive neuroectodermal tumor, or desmoplastic small round cell tumor.

Testicular and paratesticular tumors and tumor-like lesions in the first 2 decades

“…320,326 Despite the morphologic similarity of the small cells to neuroblastic cells, molecular markers for neuroblastoma, including N-myc amplification and 1p deletion, are absent, as are the translocations seen in Ewing's sarcoma and desmoplastic small round cell tumor. 327 Most cases behave in a benign fashion, although one epididymal tumor in a 17-month old did metastasize to retroperitoneal lymph nodes, 328 and another in a 6-month old invaded the lymphatics but had a clinically benign course. 323 It has been suggested that the uncommon cases of maxillary melanotic neuroectodermal tumor that behave aggressively may be prospectively recognized by elevated mitotic rates and high proliferative fractions, as assessed by Ki-67 staining.…”

Melanotic neuroectodermal tumour of infancy

“…Increased alpha-fetoprotein levels and positive staining for the c-myc antigen, characteristic of other neural crest tumours, has also been described (5,27,29,33,34). Despite these microscopic and immunohistochemical similarities, there are no shared genetic changes linking MNTI with the other neuroectodermal tumours (14,35).…”

Cytologic Interpretation of Melanotic Neuroectodermal Tumour of Infancy Involving Cranial Bones: Clue to Diagnosis

“…They detected MYCN gene amplification and deletion of 1p in all 3 cases and presence of the t(11;22)(q24;q12) and the t(11;22)(p13;q12) translocations in 2 of 3 cases . But, there was no genetic basis to link melanotic neuroectodermal tumour of infancy to neuroblastoma, Ewing sarcoma/peripheral primitive neuroectodermal tumour, or desmoplastic small round cell tumour [14].…”