A case of large cell neuroendocrine carcinoma exhibiting rhabdoid features in the esophagogastric junction

Abstract

We report a case of large cell neuroendocrine carcinoma with rhabdoid features in the esophagogastric junction. An 81‐year‐old man presented to Saku Central Hospital Advanced Care Center with a tumor in the esophagogastric junction. During upper gastrointestinal endoscopy, an ulcerative tumor, measuring 4\u2009×\u20093\u2009cm in diameter, was observed. Computed tomography revealed lymph node metastasis, but no metastasis to other organs was observed. A thoracoscopic subtotal esophagectomy was performed. Histopathologically, anaplastic large cells exhibited a solid growth pattern with focal and geographic necrosis. Approximately half of the tumor cells exhibited large nuclei with conspicuous nucleoli; an eosinophilic “rhabdoid” cytoplasmic inclusion; and a nucleus displaced eccentrically by the cytoplasmic inclusion body. Immunohistochemically, tumor cells, including rhabdoid cells, were focally positive for pan‐cytokeratin and diffusely positive for vimentin and synaptophysin. Additionally, electron microscopy identified dense‐core granules in the tumor cells. Therefore, a diagnosis of large cell neuroendocrine carcinoma with rhabdoid features was made. A few cases of esophageal neuroendocrine tumors with rhabdoid features have been reported in the lung and pancreas; however, this is the first report of large cell neuroendocrine carcinoma with rhabdoid features in the esophagogastric junction.