Esophageal Large-Cell Neuroendocrine Carcinoma Mimicking Benign Submucosal Tumor Treated With Endoscopic Submucosal Dissection

Abstract

A 68-year-old man with dysphagia was referred after being diagnosed with a submucosal tumor (SMT) in the mid-esophagus at another hospital. The initial biopsy indicated chronic inflammation, and his medical history and physical examination were unremarkable. At our hospital, endoscopy showed an SMT with a biopsy scar on the surface (Figure A). Endoscopic ultrasound (EUS) revealed a mixed-echoic lesion originating from the submucosa (Figure B). Contrast-enhanced computed tomography confirmed a uniformly enhancing soft tissue lesion without lymph node involvement (Figure C). Endoscopic submucosal dissection was performed, achieving en bloc resection without complications (Supplementary Video 1). Pathology identified the lesion as a large-cell neuroendocrine carcinoma with geographic necrosis (Figure D). Immunohistochemistry was positive for synaptophysin, cytokeratin Pan, and CD56, with a Ki-67 index of 90%. The patient refused to undergo surgery and chemotherapy as recommended. Three months later, follow-up endoscopy and computed tomography showed no recurrence or metastasis. This case highlights that esophageal large-cell neuroendocrine carcinoma, an aggressive malignancy, can mimic benign SMTs. The proximal aspect of the lesion showed uniform hyperechogenicity on EUS, indicating densely packed tumor cells on histopathology, whereas the distal part contained anechoic cystic areas, indicating geographic necrosis. Combining EUS with endoscopic submucosal dissection is valuable for diagnosing and treating SMTs of unknown nature. Jiao Li and Zhengkui Zhou contributed equally to this work. eyJraWQiOiI4ZjUxYWNhY2IzYjhiNjNlNzFlYmIzYWFmYTU5NmZmYyIsImFsZyI6IlJTMjU2In0.eyJzdWIiOiJkYzE4ZjJkMzRmYThlNDYyN2Q3M2RiYzE0YTI1ZDVkYSIsImtpZCI6IjhmNTFhY2FjYjNiOGI2M2U3MWViYjNhYWZhNTk2ZmZjIiwiZXhwIjoxNzI0MDgwNjMwfQ.elUfPS88rwx97SVCbqoctl4GQsKyIDnFWdeLJu_MzRLvT1Ivcqd1bhSuE7fgw0hf8aO3jwrwEHaQjA9FP_V4dVKeuzob5SgKgx-enF3yE5c_pxe6DNT_iNxXmAgTLGflcz7SJ1bRBAuX_QQpOI01WlBWQdWmSzFdhp8f3lRnBpo-wmS2eoaNuSVjDV8Ad_0ZIp08UdZMhc_jH0N59GIg3NdvUYMNiWpUI1OWANMMA9m-QpC7aV1v4rLw9KOfWgfE3sjEPzdZs3g7NTzEz4-lcbPRp8pKfxvPl2eMupF2al1ct0fHJoOgDZdyIjw7JDz_S3TMjfh289dHA-I-9wCPSQ Download .mp4 (10.3 MB) Help with .mp4 files Supplementary Video 1EUS and histopathologic correlation of the esophageal large-cell neuroendocrine carcinoma.