A Case of Gastric Cancer with Mediastinal Lymph Node Recurrence Four Years after Surgery Despite Pathologically Complete Response to Preoperative Chemotherapy

A 71-year-old man was diagnosed with advanced gastric cancer of the upper body of the stomach by esophagogastroduodenoscopy. CT scan showed enlarged left supraclavicular fossa and mediastinal lymph nodes. U, type 4, cT4aN2M1 (LYM), Stage ⅣB was diagnosed and chemotherapy(SOX)was administered. After chemotherapy, the distant lymph nodes shrank and PET-CT scan showed no distant lymph node involvement. ycT1bN0M0, Stage Ⅰ was diagnosed. Laparoscopic total gastrectomy D2 dissection was performed as conversion surgery. Pathological findings were ypT0N0(0/34)M0 and histological response Grade 3. As postoperative adjuvant chemotherapy, S-1 was administered for about 1 year. The left supraclavicular fossa and mediastinal lymph nodes remained reduced and patients were followed up while imaging studies were performed. Four years post-operatively, the patient was diagnosed with recurrence due to elevated tumor markers and rapid enlargement of supraclavicular fossa and mediastinal lymph nodes. We experienced a case in which the patient had a pathological complete response but recurred 4 years after surgery.