case_images: PMC9648570_01
case_images: Laryngoscope, operative field and contrast-enhanced CT. (A) Endoscopic view demonstrated a mass obstructing the laryngeal entrance. (B) CT revealed a giant tumor occluding the pharynx at the same level in A. (C) The tumor was exposed through a suprahyoid transcervical incision. (D) Cross-section of the tumor revealed a white to tan appearance.
case_images: wjps-2021-000342f01.jpg
case_images: PMC9648570_01_wjps-2021-000342f01.jpg
case_images: F1
case_images: Subsequent laryngoscopy showed an exophytic tumor located in the right piriform sinus partially covering the laryngeal entrance (figure 1A). Contrast-enhanced CT revealed a 30 mmx20 mmx20 mm mass with evident homogeneous enhancement occluding the entrance to the larynx (figure 1B). The tumor and the involved larynx were excised with the help of frozen sections to determine the safe margin (figure 1C). Macroscopically, the tumor was granular and fragile, covered by incomplete mucosa, with a white to tan gross appearance (figure 1D).
case_images: Histological and immunochemical staining. (A) Spindle cells and lymphocytes infiltration under squamous cell hyperplasia of the overlying mucosa (H&E staining, original magnification x50). (B) Spindle cells and lymphocytes infiltration (H&E staining, original magnification x400). (C) The tumor cells were positive for MSA (immunohistochemical staining, original magnification x400). (D) The tumor cells were positive for SMA (immunohistochemical staining, original magnification x400). MSA, myo-specific actin; SMA, smooth muscle actin.
case_images: wjps-2021-000342f02.jpg
case_images: PMC9648570_01_wjps-2021-000342f02.jpg
case_images: F2
case_images: Microscopically, spindle cell proliferation and inflammatory cell infiltration were observed in the tumor, while reactive hyperplasia in the lymph nodes was noted (figure 2A, B). Immunohistochemically, the spindle cells were positive for smooth muscle actin, myo-specific actin (figure 2C, D), and transducin-like enhancer of split 1 (weakly positive), and negative for anaplastic lymphoma kinase (ALK), epithelial membrane antigen, desmin, H-caldesmon, myogenin, P63, CD34, S-100, and Epstein-Barr virus-encoded RNA in situ hybridization.