[Myeloid sarcoma: report of one case with trisomy 11].

Myeloid sarcoma is a form of extra-medullary myeloid neoplasia. Cytogenetic characterization is hampered in the absence of invasion to the bone marrow, origin of cells that are usually studied in cytogenetic studies. We report a 13 years old mole presenting with a mass in the right shoulder. A biopsy of the tumor disclosed a Myeloid Sarcoma. A conventional cytogenetic study of a bone marrow aspirate did not show t (8;21) translocation. A fluorescent in situ hybridization (FISH) performed in the paraffin embedded biopsy of the tumor, detected a chromosome 11 trisomy.