A case of adenoid cystic carcinoma of the esophagus

Esophageal adenoid cystic carcinoma (EACC) is a very rare form of malignant tumor in the esophagus. Here, we report the case of a 78-year-old man who was diagnosed with EACC by preoperative endoscopic biopsy. Thoracoscopy-assisted subtotal esophagectomy with lymph node dissection was carried out. Microscopic examination of the resected specimen suggested that the tumor invaded to submucosal layer and showed no lymph node metastasis. Histologically, tumor primarily exhibited an alveolar solid pattern with partial cribriform and tubular patterns. Alcian blue staining showed many mucoid materials within the glandular cavity formed by tumor cells. Immunohistochemical studies revealed that the tumor cells reacted with pan-cytokeratin immunostains and expressed vimentin and S-100 protein. Collectively, the tumor was diagnosed as primary EACC, T1bN0M0 according to "Japanese Classification of Esophageal Cancer 10th edition." The patient showed no recurrence sign 12 months after the surgery.The current study also reviewed 35 EACC cases reported in Japanese literatures from 1990 to 2014. Combined with our case, we found that EACC is less frequently accompanied by lymph node metastasis as compared to esophageal squamous cell carcinoma, especially at the early stage. The prognosis of EACC is relatively better when tumors have no lymph node metastasis.