Esophageal Squamous Cell Carcinoma with Ductal Differentiation

Esophageal squamous cell carcinoma with ductal differentiation (ESCC-DD) is exceedingly rare. This article presents a 61-year-old man with progressive dysphagia. Imaging studies and endoscopy were suggestive of malignancy. Pathological examination of the biopsy specimen diagnosed squamous cell carcinoma with focal biphasic glandular structures. The patient received chemotherapy with albumin-bound paclitaxel plus cisplatin, combined with immunotherapy using sintilimab injection, alongside supportive care to manage treatment-related adverse effects. One month later, his dysphagia had significantly improved. Post-treatment imaging showed reduced wall thickening in the mid-to-lower thoracic esophagus. The patient subsequently underwent thoracoscopic-laparoscopic esophagectomy. The postoperative pathological diagnosis was "esophageal carcinoma post comprehensive treatment," specifically moderately differentiated squamous cell carcinoma with focal biphasic glandular structures infiltrating the muscularis propria. The primary tumor site showed a minimal treatment response (Grade 2 according to the Becker criteria) on tumor regression grading, with approximately 15%-20% residual carcinoma cells within the tumor bed, along with stromal fibrosis and a prominent inflammatory infiltrate. Regional lymph nodes were positive for metastatic carcinoma. The histogenesis of the bilayer glandular structures found in ESCC remains a subject of debate. Based on immunohistochemical and special staining, we speculate these glands originate from aberrant differentiation of multipotent stem cells within esophageal submucosal gland ducts. We provide a comprehensive analysis of the histopathological features, clinical behavior, treatment, and prognosis of ESCC-DD.