Basaloid cell carcinoma of the esophagus with a metastatic neck tumor of unknown origin: report of a case.

A 51-year-old man was admitted to our hospital with a tumor in the right anterior region of his neck. Aspiration biopsy revealed squamous cell carcinoma (SCC). Further investigations, including upper gastro-intestinal series and endoscopy, showed two flush lesions in the middle and lower thoracic esophagus. An endoscopic biopsy was done and the pathological findings indicated poorly differentiated SCC. He underwent esophagectomy with three-field lymph node dissection, including the neck tumor. Histological findings revealed that the tumor in the middle thoracic esophagus was moderately differentiated SCC, and that the other tumor below it was basaloid cell carcinoma (BCC). The depths of invasion were to the lamina propria mucosae for the former and to the submucosal layer for the latter. There was no lymphatic invasion, venous invasion, or lymph node metastasis. A diagnosis of poorly differentiated SCC of unknown origin was made for the neck tumor. Postoperative recombinant chemotherapy with cisplatin and 5-fluorouracil was given for the unknown primary site, which we still have not identified. No recurrence of the esophageal cancer has been detected.