title: [Refractory primary myeloid sarcoma of the breast with MLL-AF9 rearrangement].
abstract: A 28-year-old woman presented with a right breast mass and axillary lymphadenopathy. Biopsy of the breast mass revealed myeloid sarcoma (MS) staining positive for CD4, CD13, CD33, and CD68/KP-1. Bone marrow aspiration revealed leukemic cell infiltration (9%). Leukemic cells possessed cytogenetic abnormalities of +8 and t(9;11)(p22;q23) with +22 (lymph node only), and molecular analyses confirmed the MLL-AF9 fusion gene. After induction chemotherapy and 2(nd) consolidation therapy, complete remission was maintained. However, during consolidation radiotherapy for the breast mass, the disease progressed in both the breast and bone marrow. She received re-induction therapy and proceeded to allogeneic stem cell transplantation. However, the disease relapsed in the breast soon after transplantation, and she died from disease progression. Trisomy 8 and the MLL-AF9 fusion gene have been reported in cases with MS in the breast. Trisomy 22 found additionally and exclusively in the extramedullary lesion implies extramedullary progression of MS from the medullary site of origin and may have been associated with the distinctive therapy resistance of these lesions in our case.
authors: Department of Hematology, Tokyo Medical and Dental University.
authors: Emi
authors: E
authors: Uchida
authors: Ken
authors: K
authors: Watanabe
authors: Gaku
authors: G
authors: Oshikawa
authors: Chizuko
authors: C
authors: Sakashita
authors: Tetsuya
authors: T
authors: Kurosu
authors: Tetsuya
authors: T
authors: Fukuda
authors: Ayako
authors: A
authors: Arai
authors: Naomi
authors: N
authors: Murakami
authors: Osamu
authors: O
authors: Miura
authors: Masahide
authors: M
authors: Yamamoto
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000235:genetics* / Q000628:therapy; D017809:Fatal Outcome; D005260:Female; D018628:Gene Dosage; D015321:Gene Rearrangement; D006801:Humans; D007621:Karyotyping; D051788:Myeloid-Lymphoid Leukemia Protein / Q000235:genetics*; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D023981:Sarcoma, Myeloid / Q000235:genetics* / Q000628:therapy
chemical_list: C474558:MLL-AF9 fusion protein, human; D015514:Oncogene Proteins, Fusion; D051788:Myeloid-Lymphoid Leukemia Protein