Unusual lymph node metastasis from cancer of the thoracic esophagus

A 76-year-old male received concurrent chemoradiotherapy, at a dose of 60 Gy with low-dose 5-fluorouracil, for cT1bN0M0 squamous cell carcinoma of the mid-thoracic esophagus. Because his primary tumor relapsed with mediastinal and right supraclavicular node metastasis 4 months after completion of chemoradiotherapy, right transthoracic esophagectomy with mediastinal and right cervical lymphadenectomy was performed. However, metastatic tumors developed deep beneath the anterior border of the trapezius muscle 2 months after esophagectomy. En bloc dissection of the adipose tissue including the tumor and the transverse cervical artery was performed, followed by adjuvant radiotherapy of 50.4 Gy to the area of dissection. The patient died of pneumonia 11 months after metastasectomy, with locally recurrent disease. We have had three cases of this unusual lymph nodes metastasis from cancer of the thoracic esophagus to date and here present the characteristic imaging findings and the possible mechanism of this unusual lymph node metastasis.