CA19-9-producing esophagogastric junction cancer with nodal recurrence outside the planned dissection field: a case report.

Introduction: The biological behavior of CA19-9-producing esophagogastric junction cancer (EGJC) remains poorly understood, although some reports suggest that CA19-9 expression reflects a more aggressive subtype. Presentation of case: We report a 64-year-old man with Siewert type II EGJC, presenting with 3.5 cm of esophageal invasion and markedly elevated serum CA19-9 levels (11 630 U/mL). Following neoadjuvant chemoradiotherapy, thoracoscopic Ivor Lewis esophagectomy with lower mediastinal lymphadenectomy was performed. Histopathology confirmed a CA19-9-producing adenocarcinoma. Twenty months postoperatively, a solitary recurrence in the No.109 L mediastinal lymph node, outside the planned dissection field, was identified. Salvage lymphadenectomy via left thoracotomy achieved R0 resection. Adjuvant chemoradiotherapy was subsequently administered. The patient remains recurrence-free 38 months after the salvage surgery. Discussion: This case demonstrated nodal recurrence outside the planned dissection field despite limited esophageal invasion. The findings suggest that biological tumor characteristics, including elevated CA19-9 expression, may contribute to recurrence patterns not fully predicted by current lymphadenectomy algorithms. Moreover, timely salvage surgery in cases of solitary nodal recurrence can result in favorable long-term outcomes. Conclusion: In conclusion, CA19-9-producing EGJC may exhibit biologically aggressive features. This case suggests that elevated CA19-9 expression may represent a factor associated with recurrence beyond the planned dissection field. Further studies are needed to clarify whether tumor biology should be incorporated into surgical decision-making in EGJC.