Advanced gastric small cell carcinoma with immunotherapy-based treatment: A case report

Figure 1 Abdominal and pelvic computed tomography showing gastric mass. A: Gastric mass and lymph node involvement before treatment; B: The gastric mass disappeared after seven cycles of chemotherapy; C: The gastric tumor reappeared two months after the completion of chemotherapy; D: The tumor in the gastric body and liver shrank significantly after three cycles of new chemotherapy.

Figure 2  Esophagogastroduodenoscopic view of the gastric mass in the posterior wall of the gastric body.

Figure 3 Pathological morphology of gastric small cell carcinoma. A: Under low-power magnification, sheets of small blue cells infiltrated into the mucosa; B: Under high-power magnification, tumor cells were poorly differentiated, with scant cytoplasm and high mitosis.

Figure 4 Tumor cell expression. A: Tumor cells diffusely expressed synaptophysin; B: Tumor cells diffusely expressed INSM1.