title: Primary cutaneous Ewing's sarcoma/peripheral primitive neuroectodermal tumors in childhood. A molecular, cytogenetic, and immunohistochemical study.
abstract: Childhood cutaneous and subcutaneous malignancies are rare and include metastatic tumors of diverse histogenesis as well as primary lesions, such as sweat gland carcinomas. Some cutaneous malignancies exhibit a small round cell tumor morphology with few definitive differentiating features; they can thus pose a significant diagnostic problem. We describe two primary malignancies of the skin and superficial subcutis, which were originally diagnosed as sweat gland carcinomas on the basis of their morphological features. A cytogenetic analysis performed on one of these lesions showed the t(11;22)(q24;q12) rearrangement, believed to be unique to the Ewing's sarcoma/peripheral primitive neuroectodermal tumor (ES/pPNET) group of neoplasms. In view of this unexpected result, reverse transcriptase-polymerase chain reaction analysis was performed on both lesions and showed that they expressed EWS/FLI-1 fusion gene mRNA transcripts, the molecular equivalent of t(11;22)(q24;q12). The two tumors also had an immunohistochemical profile suggesting ES/pPNET, including strong expression of the MIC2 antigen. Both patients were treated with wide local excision, and one was given a course of chemotherapy. Neither patient showed evidence of tumor elsewhere after follow-up periods of 2 years and 16 years. These findings suggest that these tumors are indeed a form of primary ES/pPNET arising in the skin or superficial subcutis, which may be of low-grade malignancy and curable by local surgery.
mesh_terms: D001483:Base Sequence; D002648:Child; D002880:Chromosomes, Human, Pair 11 / Q000235:genetics; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007223:Infant; D008969:Molecular Sequence Data; D018242:Neuroectodermal Tumors, Primitive / Q000737:chemistry / Q000235:genetics / Q000473:pathology; D016133:Polymerase Chain Reaction; D012512:Sarcoma, Ewing / Q000737:chemistry / Q000235:genetics / Q000473:pathology; D012878:Skin Neoplasms / Q000737:chemistry / Q000235:genetics / Q000473:pathology; D013544:Sweat Gland Neoplasms / Q000737:chemistry / Q000235:genetics / Q000473:pathology; D014158:Transcription, Genetic