Case introduction:
The 53-year-old male patient had a smoking history of 30 years, with an average of 10 cigarettes per day, and no unsatisfactory clinical symptoms. Gastroduodenoscopy was performed in Wenzhou Integrated Traditional Chinese and Western Medicine hospital for routine health examination, and tumor of the lower esophagus was found. She came to Wenzhou Integrated Traditional Chinese and Western Medicine hospital for endoscopic treatment on January 19, 2021. Endoscopic results showed that a mucosal hump was observed 42cm away from the incisor, with a diameter of about 1.3*1.2cm, and the mucosa on the surface was smooth (Figure 1). Endoscopic ultrasonography showed that 42cm from the incisor of the esophagus, there was a low-echo mass originated from the muscularis mucosa, with uneven echo and clear boundary. The measured cross-section was 0.74*0.51mm (Figure 2). The initial diagnosis of it was esophageal stromal tumor, and the nature of this tumor should await the results of pathological examination. After admission, relevant preoperative examinations were completed, and endoscopic resection of lower esophageal mass was performed on January 20, 2021 after surgical contraindications were eliminated (Fig 3). Postoperative pathological findings: one grayish white nodules, diameter 0.8cm, clear boundary, no capsule, section of grayish white, soft texture. (Fig. 4) The lesion consists of variously-sized, dilated glandular lumens surrounded by dense, proliferative lymphoid tissue. The glandular lumen is filled with abundant clastic red - stained secretions. The inner wall of the glandular lumen is lined with double-layer epithelial cells, and the inner epithelial cells are atrophied. The cells are flat, cubic, and a few are columnar. The epithelial hyperplasia in the focal area folds into the lumen and shows papillary growth. The basal cells in the outer layer of the glandular lumen were flat or cubic, with round or flat nuclei, rare cytoplasm and some transparent cytoplasm. The morphology of the two layers of cells was mild and no pathological mitosis was observed. Immunohistochemical staining (Figure 5-6) showed that The inner epithelial cells of the glandular lumen cytokeratin (Cytokeratin, CK) positive, CK7 positive, P63 positive cell proportion < 1%, CD20 negative, CD117 negative, thyroid transcription factor-1 (TTF-1) negative, Lymphatic endothelial markers (D2-40) negative, tumor cell proliferation index in double epithelial cells (Ki-67) negative.