RESUMO
Extraskeletal myxoid chondrosarcomas (EMCs) are characterized histologically by a cord-like or lace-like arrangement of small round cells or short spindle cells with eosinophilic cytoplasm distributed in a rich myxoid matrix. Atypical cases of EMC have also been described, with areas of poor mucus production and high cellularity and a transition to typical EMC. Most cases of EMC harbor the chromosomal reciprocal translocation t(9;22) (q22;q12) and the resultant fused gene, Ewing sarcoma region 1-nuclear receptor subfamily 4, group A, member 3 (EWSR1-NR4A3). Other translocations, such as those involving the NR4A3 gene, have also been noted, although these occur at a lower frequency. On this basis, we conducted a fluorescence in situ hybridization (FISH) analysis of 18 cases of EMC in which patients presented with typical or atypical (areas of high cellularity) histologic features of EMC. We used an EWSR1 probe and a newly prepared NR4A3 probe to evaluate the usefulness of FISH in the pathologic diagnosis of EMC. FISH analysis using the EWSR1 or NR4A3 probe showed split signals in 83% (15/18) of the cases, regardless of the presence of typical/atypical histologic features. Gene rearrangement of EWSR1 was noted in 72% (13/18) of the cases, and rearrangement of NR4A3 was noted in 61% (11/18) of the cases. The NR4A3 rearrangement was detected in 2 cases not carrying any EWSR1 rearrangement, as determined by reverse transcription-polymerase chain reaction. These results suggest that FISH analysis of formalin-fixed, paraffin-embedded specimens using EWSR1 and NR4A3 probes is useful and convenient and may provide an ancillary method for the diagnosis of EMC.
Assuntos
Proteínas de Ligação a Calmodulina/genética , Condrossarcoma/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a RNA/genética , Receptores de Esteroides/genética , Receptores dos Hormônios Tireóideos/genética , Neoplasias de Tecidos Moles/genética , Adulto , Idoso , Condrossarcoma/diagnóstico , Feminino , Humanos , Hibridização in Situ Fluorescente , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/genética , Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/genética , Proteína EWS de Ligação a RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Neoplasias de Tecidos Moles/diagnósticoRESUMO
We report a 53-year-old Japanese woman with multiple, red, and elastic soft nodules on the left waist, left thigh, and right lower leg. She had had polyclonal hyperglobulinemia for one year, rheumatoid arthritis for 13 years, and Sjögren's syndrome (SjS) for 18 years. Histochemical examination of the nodule on the left thigh revealed a deposition of amyloid by Congo red staining. It was also positively stained with both anti-kappa and -lambda light chain antibodies. Moreover, the cytoplasm of the infiltrating plasma cells also positively reacted to both antibodies. The major amyloid proteins of primary localized cutaneous nodular amyloidosis (PLCNA) generally consist of monoclonal immunoglobulin light chains. A review of literature demonstrates 13 cases of PLCNA with SjS, in which immunoglobulin light chains were demonstrated in the amyloid in 5 cases. Amyloid in the 3 cases was composed of a single class immunoglobulin light chain and that in the 2 cases was composed of both kappa and lambda light chains. Polyclonal immunoglobulin amyloid has been reported only in PLCNA with SjS, which may be related to the fact that a certain population of SjS develops polyclonal B cell proliferation and hyperglobulinemia.