Esophageal Large-Cell Neuroendocrine Carcinoma with Inconsistent Response to Treatment in the Primary and Metastatic Lesions

Esophageal large-cell neuroendocrine carcinoma (NEC) is a rare malignant tumor that is characterized by high-grade malignancy and a poor prognosis. However, the rarity of esophageal NEC has prevented the development of an established treatment, and no reports have described a discrepancy in the effectiveness of cisplatin plus irinotecan between primary and metastatic lesions. A 43-year-old Japanese man was referred to our hospital with refractory epigastralgia. A previous gastrointestinal endoscopy had revealed a 50-mm type 2 tumor in the abdominal esophagus. The pathological findings indicated poorly differentiated squamous cell carcinoma. Contrast-enhanced computed tomography revealed a metastatic liver tumor. One cycle of fluorouracil and cisplatin was not effective, and endoscopy was repeatedly performed. The pathological findings indicated a large-cell malignant tumor with tumor cells that were positive for CD56, synaptophysin, and Ki-67 (> 80%). Based on a diagnosis of esophageal large-cell NEC with a metastatic liver tumor, the patient received cisplatin plus irinotecan biweekly. After 4 months, computed tomography revealed marked shrinkage of the metastatic tumor, but the patient complained of dysphagia. Endoscopy revealed enlargement of the primary tumor, which was then treated using radiotherapy plus fluorouracil and cisplatin. The primary tumor subsequently shrank, and the patient's symptoms were relieved, but the metastatic tumor grew. Thus, chemoradiotherapy could be an option for managing a primary esophageal large-cell NEC that does not respond to chemotherapy alone. However, the possibility of an inconsistent response to therapy in primary and metastatic lesions should be considered.