DEK::AFF2 fusion-associated middle ear non-keratinizing squamous cell carcinoma: A case report

Figure 1 The magnetic resonance imaging and macroscopic view of the tumor. A: magnetic resonance enhanced scan of the inner ear canal showing a space-occupying lesion in the left external auditory canal (orange arrow); B: Macroscopic view of the tumor (orange circle).

Figure 2 Histological examination of the tumor. A: Histological analysis showed the tumor manifested as an endophytic papillary carcinoma resembling transitional epithelium with inverted nest-like proliferation patterns; B: The basal cells exhibited fence-like arrangements, interspersed with extensive areas of necrosis; C: Inflammatory cells, including lymphocytes, plasma cells, and neutrophils, were considerably present in both the epithelial and stromal layers.

Figure 3 Immunohistochemical staining and fluorescence in situ hybridization testing of the tumor. A: Immunohistochemical staining showing tumor cells positive for AFF2 (EnVision method, medium magnification); B: Immunohistochemical staining showing tumor cells positive for programmed death-ligand 1 (EnVision method, medium magnification); C Fluorescence in situ hybridization testing revealing disruption within the DEK gene structure.

Figure 4 Computed tomography scan of metastatic lesions. The computed tomography scan shows thoracic vertebral metastatic lesions (orange arrow).