PMC9798229_01
The CT scan of CDS. (A) An irregular lobulated mass in pelvic cavity, which has unclear margin with peripheral structure, is shown. (B) The tumor shows heterogeneous enhancement in the contrast-enhanced CT scan.
fonc-12-1018992-g001.jpg
PMC9798229_01_fonc-12-1018992-g001.jpg
f1
Asian girl came to the hospital with complaints of abdominal pain. A computed tomography (CT) scan showed a cystic and solid mass measured 12.1 cm x 8.2 cm x 13.6 cm in the pelvic cavity with heterogeneous enhancement in an enhanced scan ( Figure 1 ).
The histopathology and immunohistology of CDS. (A) At low magnification, the tumor cells are separated by massive necrosis, arranged in nest-like and perivascular (H&E, x40). (B) Focal myxoid stroma (H&E, x40). (C) At high magnification, the tumor cells show round-to-oval shape with lightly eosinophilic cytoplasm and vesicular nuclei; several mitotic figures are visible (H&E, x400). Moreover, (D) spindle cell-like (H&E, x200), (E) clear cell-like (H&E, x200), and (F) rhabdoid plasmacytoid tumor cells (H&E, x200) are also exhibited in some areas. (G) CD99 is focally membranous positive (IHC, x400). (H) WT-1 (IHC, x200) and (I) Fli-1 (IHC, x200) are diffusely nuclear positive. IHC, immunohistochemistry.
fonc-12-1018992-g002.jpg
PMC9798229_01_fonc-12-1018992-g002.jpg
f2
Moreover, necrosis and pathologic mitoses were apparent ( Figures 2A-F ). Immunohistochemical (IHC) staining showed diffusely positive for vimentin, Fli-1, cyclin D1, and WT-1 and very focally positive for CD99 ( Figures 2G-I ). Figure 3A ), 2) LongInDel of POLE (exon22_exon31del) ( Figure 3B ), 3) copy number variation (CNV) of CD79A (5.8 copies), 4) low tumor mutational burden (TMB) at 0.5 Muts/Mb, and 5) microsatellite stability (MSS). Finally, this tumor was diagnosed as CDS.
The genetic changes of the case. (A) The case shows a classical fusion of CIC-DUX4, which is generated by translocation of chromosome t(4;19)(q35;q13). The breakpoints are located in exon 20 of CIC and exon 1 of DUX4, respectively. (B) The LongInDel of POLE (exon22_exon31del) causes deletion of amino acid residues 823-1,335 of POLE protein, which may lead to frameshift and loss of polymerase domain 25 and CysB motif (amino acid residues 2,221-2,238).
fonc-12-1018992-g003.jpg
PMC9798229_01_fonc-12-1018992-g003.jpg
f3
Figure 3A ), 2) LongInDel of POLE (exon22_exon31del) ( Figure 3B ), 3) copy number variation (CNV) of CD79A (5.8 copies), 4) low tumor mutational burden (TMB) at 0.5 Muts/Mb, and 5) microsatellite stability (MSS). Finally, this tumor was diagnosed as CDS.