Correlation of Classic and Molecular Cytogenetic Alterations in Soft-Tissue Sarcomas: Analysis of 46 Tumors With Emphasis on Adipocytic Tumors and Synovial Sarcoma.

INTRODUCTION: Sarcomas are heterogeneous, and their treatment and prognosis are driven by the morphologic subtype and the clinical stage. Classic cytogenetics and fluorescence in situ hybridization (FISH) analysis play an important role in their diagnostic work up. MATERIALS AND METHODS: Forty-six cases of soft-tissue sarcoma were reviewed that underwent karyotyping and simultaneous FISH analysis at initial diagnosis. They included 10 dedifferentiated liposarcomas, 10 myxoid liposarcomas, and 14 synovial sarcomas. Six tumors were investigated for EWSR1 rearrangement. Six high-grade miscellaneous sarcomas were also examined. RESULTS: The dedifferentiated liposarcoma had complex karyotypes and MDM2 amplification by FISH, and of these, 5 tumors with myxoid changes also had complex signals for DDIT3. All but 4 myxoid liposarcomas had complex karyotypes, in addition to the characteristic translocation. FISH analysis displayed DD1T3 rearrangement. All synovial sarcomas except 1 recurrence had a t(X;18) translocation by karyotyping and FISH. The EWSR1 rearrangement was present in all extraskeletal myxoid chondrosarcomas, angiomatoid fibrous histiocytoma, atypical Ewing sarcoma, and a clear-cell sarcoma, all of which had characteristic karyotypes. Seven high-grade sarcomas had no specific karyotype or rearrangements for DDIT3, SS18, and EWSR1 by FISH. CONCLUSIONS: There is good correlation between karyotyping and FISH. Complex FISH signals found in dedifferentiated liposarcomas may be related to an increased chromosome 12 copy number and ploidy. Karyotyping is an important baseline standard for the quality assurance of newly developed FISH probes. It also provides a global view of chromosomal changes and the opportunity to investigate the role of other genetic alterations and potential therapeutic targets.

Lipoblastoma: un raro tumor pediátrico / Lipoblastoma: a rare pediatric tumor

Desde las primeras descripciones en 1926 de un raro tumor de células adiposas inmaduras, de presentación casi exclusiva en la edad pediátrica, se han descrito cerca de 200 casos en la literatura. 60-80% de los lipoblastomas se presentan antes de los 3 años de edad, con cierta predilección por el sexo masculino. Estos tumores denominados Lipoblastomas se presentan en dos formas clínicas: los tumores circunscritos, subcutáneos, de localización preferencial en las extremidades (70%) la forma infiltrativa y difusa de localización más bien profunda denominada Lipoblastomatosis (30%). La característica microscópica es la presencia de lipoblastos, separados por septos y rodeados de una fina red vascular. Otros exámenes auxiliares no son de ayuda en el diagnóstico. La microscopiano puede diferenciarlos de otros tumores malignos como el liposarcoma, por lo cual la citogenética es una tecnología de gran ayuda, demostrando alteración del cromosoma 8 (8q 11-13), con reordenamiento del gen PLAG1. El tratamiento es quirúrgico, presentándose recidivas hasta en 33% de los casos, por lo cual se recomienda seguimiento por 2-5 años. Otras formas de tratamiento no han probado eficacia.

Since the first description in 1926 of a rare tumor of immature fat cells with exclusive presentation in pediatric patients, 200 cases have been described in the literature. 60 - 80% of lipoblastomas appear before 3 years of age, with slight predilection formales. These tumors are called lipoblastomas and have 2 clinical presentations, the circumscribed subcutaneous tumors in the extremities (70%) and the infiltrative and diffuse tumors in deep locations named lipoblastomatosis (30%). The microscopic characteristic is the presence of lipoblasts, separated by septums and surrounded by a thin vascular net. Other ancillary exams are not help fulfor the diagnosis. The microscopic exam cannot differentiate lipoblastoma from other malignant tumors such as liposarcoma. Cytogenetics can be helpful for the differentiation, showing alterations in the 8th chromosome (8q 11-13) with rearrangement of PLAG1 gene. The treatment is surgical, witha relapse rate up to 33%; the refore a 2 to 5 year follow up is recommended. Other treatments are not efficacious.

Liposarcoma primario de mesenterio: reporte de un caso / Primary mesenteric mixto liposarcoma: report of a case

Los liposarcoma primarios de mesenterio son neoplasias muy raras poco frecuentes de ver. En el presente trabajo reportamos un caso donde un paciente se presenta con una historia, al ingreso hospitalario, de politraumatismo.

Caso incomum de lipoma associado ao nervo mentoniano: uma revisäo / Unusual case of lipoma associated with the mentoniani nerve: a review

Um caso raro de lipoma intrabucal associado ao nervo mentoniano, causando sintomatologia dolorosa, assim como, uma revisäo de literatura mostrando a discutida etiopatogenia desta alteraçäo é apresentado