Loại này được xếp loại tốt, trung bình hoặc kém phân biệt, theo tỷ lệ của các tế bào khối u hình thành tuyến (hình và b). Bướu có thể mucinous với hồ mucin nổi bật ngoại bào. Signet vòng ung thư biểu mô tế bào là rất hiếm [43] | Pathology of Esophageal Cancer 21 Metaplastic or dysplastic glandular epithelium may persist beneath the new squamous epithelium hence deep biopsies are required on follow-up. Currently the long-term behavior of this concealed glandular epithelium is unknown. Invasive adenocarcinoma Macroscopic appearance Most tumors are advanced at the time of presentation and are ulcerating infiltrative lesions Figure . They are less frequently exophytic 10-15 compared with squamous cell carcinomas 41 . Rarely they appear papillary or show diffuse infiltration resembling gastric linitis plastica 42 . Microscopic appearance Adenocarcinomas are graded as well moderately or poorly differentiated according to the proportion of tumor cells forming glands Figure and b . Tumors can be mucinous with prominent extracellular mucin pools. Signet ring cell carcinoma is rare 43 . Very rarely CLE-associated adenocarcinoma may have foci of admixed choriocarcinoma 44 45 . Small cell carcinoma This accounts for approximately 1 of primary esophageal carcinomas 46 . It has a similar appearance to the more common pulmonary tumor and is highly aggressive. a Figure Invasive adenocarcinoma. a Well-differentiated adenocarcinoma composed of infiltrating glands with mild cytological atypia. b Poorly differentiated adenocarcinoma composed of sheets of cells without gland formation. b 22 . Deere Staging The TNM system is used for staging 47 . The Siewert classification is recommended for adenocarcinoma around the esophagogastric junction 48 . Tumors arising 1-5 cm above the junction type 1 are staged with the esophageal TNM whilst the gastric TNM system is recommended for tumors arising at the junction type 2 or 2-5 cm below type 3 . Proformas have been developed to ensure that all relevant prognostic information is included in pathology reports 49 50 . Prognostic factors Depth of tumor invasion is the most important and often the only independent prognostic indicator on multivariate .
