case_images: PMC6358413_01
case_images: Axial CT of the paranasal sinuses showing the tumor mass affecting the right-sided nasal cavity and nasopharynx. A new bone-like material can be seen in the nasopharynx, without bony erosion involvement of the nasal septum, orbital, and skull base. CT = computed tomography.
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case_images: F1
case_images: A computed tomography (CT) scan (Fig. 1) of the paranasal sinuses showed a mass (right inflammatory polyp and calcification) involving the nasal cavity, the right maxillary sinusitis, and ethmoid sinusitis.
case_images: Erosive necrosis and defects (due to the preoperative biopsy) can be seen in the anterior segment of the tumor.
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case_images: F2
case_images: During the operation, a polypoid tumor of the right nasal cavity was seen, including erosion and necrosis of the surface of the anterior segment of the tumor, completely blocking the right nasal cavity (Fig. 2).
case_images: The nasopharyngeal neoplastic tissue was slightly yellowish and harder than a nasal polyp.
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case_images: F3
case_images: The tumor was removed with a microdebrider; there was less bleeding when the microdebrider was used to cut the nasal cavity and nasopharyngeal mass (Fig. 3).
case_images: The nasopharyngeal mass was removed and the new bone at the bottom can be seen.
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case_images: F4
case_images: The bone was loose (Fig. 4), and its surface was uneven; further, there was a small amount of bleeding in the bone bed wound.
case_images: (HE 10*40) Histological findings. The tumor exhibited hyper-cellularity and increased mitotic activity. A large number of spindle-shaped cells with a high nuclear-to-cytoplasmic ratio were arranged in short and long fascicles.
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case_images: F5
case_images: A large number of spindle-shaped cells with a high nuclear to cytoplasmic ratio were arranged in short and long fascicles (Fig. 5) with indistinct cytoplasmic border and varying degree of nuclear pleomorphism.
case_images: Immunohistochemical staining showing positive vimentin.
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case_images: F6
case_images: Further immunohistochemical analysis revealed that the mesenchymal marker vimentin and the neuroectodermal marker soluble protein-100 (S-100) and protein gene product (PGP) 9.5 were positive (Figs. 6-8).
case_images: Immunohistochemical staining showing positive S-100. S-100 = soluble protein-100.
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case_images: F7
case_images: Further immunohistochemical analysis revealed that the mesenchymal marker vimentin and the neuroectodermal marker soluble protein-100 (S-100) and protein gene product (PGP) 9.5 were positive (Figs. 6-8).
case_images: Immunohistochemical staining showing positive PGP9.5. PGP9.5 = protein gene product9.5.
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case_images: F8
case_images: Further immunohistochemical analysis revealed that the mesenchymal marker vimentin and the neuroectodermal marker soluble protein-100 (S-100) and protein gene product (PGP) 9.5 were positive (Figs. 6-8).
case_images: Axial CT of the paranasal sinuses showing no neoplastic recurrence in the right nasal cavity and nasopharynx at 9 months after surgery. CT = computed tomography.
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case_images: F9
case_images: Recurrence of the tumor was not found on CT examinations performed at 9 months after the operation (Fig. 9).