case_images: PMC11333213_01
case_images: Magnetic resonance imaging (MRI) with contrast enhancement. Preoperative MRI showed a protruding mass above the sella turcica [(A) coronal view, (B) sagittal view]. (C-F) Representative pathological findings. Hematoxylin-eosin staining showed a tumor composed of small round cells and islands of well-differentiated hyaline cartilage with atypical chondroid cells floating in lacunar spaces (original magnification, x200) (C). A neoplastic cartilage cells do not show higher nuclear atypia, but they have constricted nuclei (original magnification, x200) (D). Areas of dense proliferation of spindle cells are also encountered (original magnification, x200) (E). A hemangiopericytomatous proliferation pattern is also noted (original magnification, x200) (F). SOX9 immunohistochemistry shows positive staining in both spindle cell and cartilaginous areas, whereas NKX3.1 immunohistochemistry shows positive staining almost only in spindle cell area (original magnification, x200, each) (G).
case_images: pore-30-1611730-g001.jpg
case_images: PMC11333213_01_pore-30-1611730-g001.jpg
case_images: F1
case_images: Magnetic resonance imaging (MRI) of the brain revealed a mass protruding over the sella turcica, with the normal pituitary gland pressed to the upper right and the optic chiasm pressed to the upper left (Figures 1A, B). A hemangiopericytomatous proliferation pattern was also noted (Figures 1C-F). Then, additional immunohistochemical examinations were performed, and positive stainings for SOX9 and NKX3.1 were confirmed (Figures 1G, H).
case_images: Identification of HEY1::NCOA2 fusion using reverse transcription-polymerase chain reaction (RT-PCR) followed by direct sequencing. RT-PCR was performed using HEY1(ex4)::NCOA2(ex13) fusion- and HEY1(ex4)::NCOA2(ex14) fusion-specific primer pairs. Anticipated sizes for each RT-PCR product were 293 and 257 bp, respectively (A). Sequence analysis demonstrated that exon 4 of HEY1 was fused to exon 13 of NCOA2
  (B) and exon 14 of NCOA2
  (C).
case_images: pore-30-1611730-g002.jpg
case_images: PMC11333213_01_pore-30-1611730-g002.jpg
case_images: F2
case_images: Both alterations were confirmed as in-frame fusions by RT-PCR using the following primer pairs: 5'-ACCGGATCAATAACAGTTTG-3' (HEY1-F1) and 5'-GTGATACCTCAGCCAGGA-3' (NCOA2-R1) and 5'-CCGAGATCCTGCAGATGACC-3' (HEY1-F2) and 5'-GCCAAAGACAGACGCTTCAG-3' (NCOA2-R2) (Figures 2A-C).