Ewing sarcoma and sinonasal neuroectodermal tumors as second malignant tumors after retinoblastoma and other neoplasms

Background. Excesses of various childhood cancers have been reported after retinoblastoma, including a trickle of Ewing sarcoma (ES) and perhaps histo logically similar olfactory neuroblastoma, both of which are neural tumors. To update and advance this information, case reports were sought by an ext ensive review of the literature. Procedure. The search was made through the use of PubMed, and the Web of Science (Citation Index Expanded), keying on primary references. Three sinonasal cancers diagnosed as ES were immunohis tochemically stained for MIC-2 protein (positive in ES). Results. Retinobla stoma occurred before ES in ten cases (seven bilateral). In four others, re tinoblastoma (three bilateral) developed before sinonasal neural tumors (po orly differentiated). ES also occurred after 14 cancers other than retinobl astoma (five lymphomas, four leukemias, and one each of five miscellaneous cancers). The predominance of retinoblastoma prior to ES differs markedly f rom the low-frequency of retinoblastoma among childhood cancers in the gene ral population. On the contrary, cancers other than retinoblastoma were pro portionate to those in the general population. Previously, retinoblastoma f ollowed by excesses of osteosarcoma and soft tissue sarcomas has been attri buted to the action of the inherited RB-1 gene. The sinonasal tumors staine d negative for MIC-2 protein. Conclusions, Heritable retinoblastoma may pre dispose to ES and perhaps to a subset of poorly differentiated neuroectoder mal tumors in the sinonasal region that may be related to olfactory neurobl astoma. Med. Pediatr. Oncol. 36:290-294, 2001. (C) 2001 Wiley-Liss, Inc.