TY - JOUR
T1 - Recurrent BCOR Internal Tandem Duplication and YWHAE - NUTM2B Fusions in Soft Tissue Undifferentiated Round Cell Sarcoma of Infancy
T2 - Overlapping Genetic Features with Clear Cell Sarcoma of Kidney
AU - Kao, Yu Chien
AU - Sung, Yun Shao
AU - Zhang, Lei
AU - Huang, Shih Chiang
AU - Argani, Pedram
AU - Chung, Catherine T.
AU - Graf, Nicole S.
AU - Wright, Dale C.
AU - Kellie, Stewart J.
AU - Agaram, Narasimhan P.
AU - Ludwig, Kathrin
AU - Zin, Angelica
AU - Alaggio, Rita
AU - Antonescu, Cristina R.
N1 - Publisher Copyright:
Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.
PY - 2016/8/1
Y1 - 2016/8/1
N2 - Soft tissue undifferentiated round cell sarcoma (URCS) occurring in infants is a heterogenous group of tumors, often lacking known genetic abnormalities. On the basis of a t(10;17;14) karyotype in a pelvic URCS of a 4-month-old boy showing similar breakpoints with clear cell sarcoma of kidney (CCSK), we have investigated the possibility of shared genetic abnormalities in CCSK and soft tissue URCS. Most CCSKs are characterized by BCOR exon 16 internal tandem duplications (ITDs), whereas a smaller subset shows YWHAE-NUTM2B/E fusions. Because of overlapping clinicopathologic features, we have also investigated these genetic alterations in the so-called primitive myxoid mesenchymal tumor of infancy (PMMTI). Among the 22 infantile URCSs and 7 PMMTIs selected, RNA sequencing was performed in 5 and 2 cases, with frozen tissue, respectively. The remaining cases with archival material were tested for YWHAE-NUTM2B/E by fluorescence in situ hybridization (FISH) or reverse transcription-polymerase chain reaction (RT-PCR), and BCOR ITD by PCR. A control group of 4 CCSKs and 14 URCSs in older children or adults without known gene fusion and 20 other sarcomas with similar histomorphology or age at presentation were also tested. A YWHAENUTM2B fusion was confirmed in the index case by FISH and RT-PCR, whereas BCOR ITD was lacking. An identical YWHAE-NUTM2B fusion was found in another URCS case of a 5-month-old girl with a back lesion. The remaining cases and control group lacked YWHAE gene rearrangements; instead, consistent BCOR ITDs, similar to CCSK, were found in 15/29 (52%) infantile sarcoma cases (9/22 infantile URCS and 6/7 PMMTI). In the control cohort, BCOR ITD was found only in 3 CCSK cases but not in the other sarcomas. Histologically, URCS with both genotypes and PMMTI shared significant histologic overlap, with uniform small blue round cells with fine chromatin and indistinct nucleoli. A prominent capillary network similar to CCSK, rosette structures, and varying degree of myxoid change were occasionally seen. BCOR ITD-positive tumors occurred preferentially in the somatic soft tissue of the trunk, abdomen, and head and neck, sparing the extremities. RNAseq showed high BCOR mRNA levels in BCOR ITD- positive cases, compared with other URCSs. In summary, we report recurrent BCOR exon 16 ITD and YWHAE-NUTM2B fusions in half of infantile soft tissue URCS and most PMMTI cases, but not in other pediatric sarcomas. These findings suggest a significant overlap between infantile URCS and CCSK, such as age at presentation, histologic features, and genetic signature, thus raising the possibility of a soft tissue counterpart to CCSK.
AB - Soft tissue undifferentiated round cell sarcoma (URCS) occurring in infants is a heterogenous group of tumors, often lacking known genetic abnormalities. On the basis of a t(10;17;14) karyotype in a pelvic URCS of a 4-month-old boy showing similar breakpoints with clear cell sarcoma of kidney (CCSK), we have investigated the possibility of shared genetic abnormalities in CCSK and soft tissue URCS. Most CCSKs are characterized by BCOR exon 16 internal tandem duplications (ITDs), whereas a smaller subset shows YWHAE-NUTM2B/E fusions. Because of overlapping clinicopathologic features, we have also investigated these genetic alterations in the so-called primitive myxoid mesenchymal tumor of infancy (PMMTI). Among the 22 infantile URCSs and 7 PMMTIs selected, RNA sequencing was performed in 5 and 2 cases, with frozen tissue, respectively. The remaining cases with archival material were tested for YWHAE-NUTM2B/E by fluorescence in situ hybridization (FISH) or reverse transcription-polymerase chain reaction (RT-PCR), and BCOR ITD by PCR. A control group of 4 CCSKs and 14 URCSs in older children or adults without known gene fusion and 20 other sarcomas with similar histomorphology or age at presentation were also tested. A YWHAENUTM2B fusion was confirmed in the index case by FISH and RT-PCR, whereas BCOR ITD was lacking. An identical YWHAE-NUTM2B fusion was found in another URCS case of a 5-month-old girl with a back lesion. The remaining cases and control group lacked YWHAE gene rearrangements; instead, consistent BCOR ITDs, similar to CCSK, were found in 15/29 (52%) infantile sarcoma cases (9/22 infantile URCS and 6/7 PMMTI). In the control cohort, BCOR ITD was found only in 3 CCSK cases but not in the other sarcomas. Histologically, URCS with both genotypes and PMMTI shared significant histologic overlap, with uniform small blue round cells with fine chromatin and indistinct nucleoli. A prominent capillary network similar to CCSK, rosette structures, and varying degree of myxoid change were occasionally seen. BCOR ITD-positive tumors occurred preferentially in the somatic soft tissue of the trunk, abdomen, and head and neck, sparing the extremities. RNAseq showed high BCOR mRNA levels in BCOR ITD- positive cases, compared with other URCSs. In summary, we report recurrent BCOR exon 16 ITD and YWHAE-NUTM2B fusions in half of infantile soft tissue URCS and most PMMTI cases, but not in other pediatric sarcomas. These findings suggest a significant overlap between infantile URCS and CCSK, such as age at presentation, histologic features, and genetic signature, thus raising the possibility of a soft tissue counterpart to CCSK.
KW - BCOR ITD
KW - YWHAE
KW - clear cell sarcoma kidney
KW - infantile
KW - primitive mesenchymal myxoid tumor of infancy
KW - small blue round cell tumor
KW - undifferentiated sarcoma
UR - http://www.scopus.com/inward/record.url?scp=84960154733&partnerID=8YFLogxK
U2 - 10.1097/PAS.0000000000000629
DO - 10.1097/PAS.0000000000000629
M3 - 文章
C2 - 26945340
AN - SCOPUS:84960154733
SN - 0147-5185
VL - 40
SP - 1009
EP - 1020
JO - American Journal of Surgical Pathology
JF - American Journal of Surgical Pathology
IS - 8
ER -