title: Conversion to Neuroendocrine Carcinoma from Squamous Cell Carcinoma of the Esophagus After Definitive Chemoradiotherapy.
abstract: OBJECTIVE
  Neuroendocrine carcinoma (NEC) of the esophagus is rare and aggressive. We herein report a case of a patient who showed NEC conversion from squamous cell carcinoma (SCC) of the esophagus in the recurrent lesion after definitive chemoradiotherapy.
  
  
  METHODS
  The patient was a 57-year-old Japanese male with mid-thoracic esophageal carcinoma diagnosed as SCC with invasion of the submucosal layer. After definitive chemoradiotherapy, the esophageal tumor completely disappeared. Two months later, local recurrence was recognized at the same location and salvage surgery was performed. An immunohistochemical examination of the resected specimen revealed that most of the recurrent tumor had neuroendocrine (NE) differentiation, although a retrospective review of the initial biopsy specimen showed no involvement of NE differentiation.
  
  
  CONCLUSIONS
  This case is significant not only in bringing attention to the possibility of NEC conversion from SCC after chemoradiotherapy, but also in discussing tumors originating in the esophagus.
authors.affiliation: Department of Gastroenterological Surgery, National Kyushu Cancer Center, Fukuoka, Japan masarum@nk-cc.go.jp.
authors.forename: Masaru
authors.initials: M
authors.lastname: Morita
authors.affiliation: Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Saeki
authors.affiliation: Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan Department of Clinical Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Y U
authors.initials: YU
authors.lastname: Nakaji
authors.affiliation: Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan Department of Clinical Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Zaitsu
authors.affiliation: Department of Clinical Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Minako
authors.initials: M
authors.lastname: Hirahashi
authors.affiliation: Department of Radiology, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Ohguri
authors.affiliation: Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Oki
authors.affiliation: Department of Gastroenterological Surgery, National Kyushu Cancer Center, Fukuoka, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Toh
authors.affiliation: Department of Clinical Pathology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Yoshinao
authors.initials: Y
authors.lastname: Oda
authors.affiliation: Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Maehara
mesh_terms: D018278:Carcinoma, Neuroendocrine / Q000139:chemically induced / Q000175:diagnosis / Q000473:pathology*; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000473:pathology* / Q000532:radiotherapy; D059248:Chemoradiotherapy / Q000009:adverse effects; D004938:Esophageal Neoplasms / Q000188:drug therapy / Q000473:pathology* / Q000532:radiotherapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000139:chemically induced / Q000175:diagnosis / Q000473:pathology*
keywords: Esophagus; chemoradiotherapy; neuroendocrine carcinoma; salvage surgery; small cell carcinoma