Duplication of chromosome segment 12q13-15 in a lipomatous tumor with minimal nuclear atypia: A case report

作者：Nishio Jun^*; Iwasaki Hiroshi; Shibata Terufumi; Nabeshima Kazuki; Naito Masatoshi

来源：Oncology Letters, 2016, 11(4): 2875-2878.

DOI：10.3892/ol.2016.4305

• lipomatous tumor
• chromosome 12q13-15
• duplication
• spectral karyotyping
• murine double-minute 2

Ordinary lipoma is cytogenetically characterized by structural rearrangements, particularly translocations, of 12q13-15. By contrast, atypical lipomatous tumors exhibit supernumerary ring or giant marker chromosomes that are composed mainly of amplified material from the 12q13-15 chromosome segment. The present study describes the cytogenetic and molecular cytogenetic findings from a lipomatous tumor with minimal nuclear atypia that was identified in a 49-year-old female patient. Magnetic resonance imaging of the right shoulder revealed a 13-cm fatty mass in the subcutaneous layer that possessed only pencil-line septa. Contrast-enhanced fat-suppressed T1-weighted images demonstrated faint enhancement. A marginal excision was performed. Histologically, the tumor was composed of lobules that consisted of mature adipocytes separated by thin fibrous septa. There was minimal nuclear atypia in certain cells, and a small number of binucleated cells were also observed within the tumor. Immunohistochemically, the tumor cells did not reveal the expression of murine double-minute 2 (MDM2). Cytogenetic analysis revealed a complex karyotype with several numerical and structural alterations, including 12q rearrangements. Spectral karyotyping demonstrated a duplication of chromosome segment 12q13-15. Interphase fluorescence in situ hybridization analysis revealed no MDM2 gene amplification. The present case indicates that duplication of 12q may be associated with minimal nuclear atypia in a subset of lipomatous tumors.

• 出版日期2016-4