High expression of squamous cell carcinoma antigen in poorly differentiated adenocarcinoma of the stomach: A case report

Figure 1 Endoscopic findings of the patient. Endoscopy showed a large, irregular, raised ulcer 25 mm × 25 mm in dimension at the antrum-body junction.

Figure 2 Findings from preoperative abdominal computed tomography. Abdominal contrast-enhanced computed tomography revealed irregular thickening and enhancement of the wall (arrow).

Figure 3 Histological characteristics. Hematoxylin and eosin stain indicated poorly differentiated adenocarcinoma with signet ring cells (200 × magnification).

Figure 4 Immunohistochemical staining characteristics. A: Immunohistochemical (IHC) staining showed strong squamous cell carcinoma antigen expression (+++) mainly in the cytoplasm of tumor cells (200 × magnification); B-D: IHC staining showed that the tumor cells were negative for p40, p63, and CK5/6 (200 × magnification); E and F: IHC staining showed that the tumor cells were positive for E-cadherin and carcinoembryonic antigen (200 × magnification).

Figure 5 Immunohistochemical staining for squamous cell carcinoma antigen in gastritis and gastric cancer tissues. Paraffin-sections from gastritis and gastric cancer tissues of multiple patients were simultaneously stained for squamous cell carcinoma antigen (SCCA). A: Negative SCCA expression (-) in well differentiated gastric cancer (200 × magnification); B: Weakly positive SCCA expression (+) in poorly differentiated gastric cancer (200 × magnification); C: Negative SCCA expression (-) in chronic gastritis (200 × magnification); D: Strong SCCA expression (+++) in gastric squamous cell carcinoma (200 × magnification).