Amplification of MYCL in Atypical Ewing Tumor. Analysis of Metaphase and Microarray Comparative Genomic Hybridization

A 20-year-old man developed a soft tissue mass in his right upper arm and, 3 months later, was referred to our hospital. The tumor cells showed brisk mitotic activity and a large amount of cytoplasmic glycogen was demonstrated with periodic acid Schiff stain. A diagnosis of atypical Ewing sarcoma was made. Chemotherapy according to the VACA protocol, comprising vincristine, actinomycin D, cyclophosphamide and doxorubicin was started. The chemotherapy was effective and a limb salvage procedure was performed by implantation of an autoclaved bone after wide tumor excision. During the postoperative chemotherapy, a local recurrence and multiple metastases developed, and the patient died due to disease progression. Fourteen years later, this tumor sample, preserved in a deep-freeze, was analyzed by reverse-transcriptase polymerase chain reaction (RT-PCR) to detect the fusion gene. This tumor had an EWS exon 7 to FLI1 exon 6 fusion transcript. Moreover, metaphase and microarray comparative genomic hybridization (CGH) was done to detect chromosomal instabilities. Many gains and losses were noted on metaphase CGH, and MYCL amplification was identified on microarray CGH.