Synchronous asymptomatic colonic metastasis from primary esophageal squamous cell carcinoma
A 64-year-old male consulted one of our hospitals due to progressive dysphagia in August 2012. An endoscopic examination revealed middle thoracic ESCC (Fig. ). Computed tomography (CT) scans showed possible invasion of the aorta and multiple lymph node metastases (T4bN3M1 stage4) (Fig. ). The length of the tumor was ∼10 cm on CT scans. The patient received definitive chemoradiotherapy [two courses of cisplatin and 5-fluorouracil (FP) plus 50.4 Gy] followed by one course of FP chemotherapy, and incomplete response/stable disease was achieved. Although an endoscopic biopsy specimen was positive for cancer (Fig. ), post-treatment CT showed no invasion of the aorta. Fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) also suggested that the size of the tumor was diminished. The patient underwent colonoscopy to prepare for colonic interposition because the radiation field included the upper part of the stomach. Preoperative colonoscopy revealed a 1.0-cm submucosal tumor at the splenic flexure, and biopsy results indicated possible metastasis from primary ESCC (Fig. ). The submucosal lesion was positive for cytokeratin 5/6 (CK5/6), CK14 and p63, and negative for CK20 and Caudal type homeobox 2 (CDX2) (Fig. ). Colonic metastasis was not detected by FDG-PET before or after chemoradiotherapy. No other obvious hematogenic metastases were noted after chemoradiotherapy.\nThe patient underwent subtotal esophagectomy by right thoracotomy with thoraco-abdominal lymph node dissection and reconstruction with a gastric tube in January 2013. Local excision of the colonic submucosal tumor was also performed (Fig. ). A postoperative pathological diagnosis revealed that the colonic tumor metastasized from primary ESCC and remnant viable carcinoma cells were found in the primary site of the esophagus and lymph nodes (Fig. ). Even though the patient was discharged 18 days after surgery without any complications, he died on the 72nd postoperative day due to multiple bone metastases and pleural dissemination.