title: Primary large cell neuroendocrine carcinoma of the ureter.
abstract: Large cell neuroendocrine carcinoma (LCNEC) is the rarest type of urinary tract malignancy. Herein, we report a case of LCNEC that arose in the ureter of a 78-year-old Japanese man with a history of ascending colon cancer that had been excised by a right hemicolectomy. Left-sided hydronephrosis associated with the ureteral tumor was discovered during follow-up. A left nephroureterectomy combined with a partial resection of the urinary bladder was performed because atypical cells were detected using voided urine cytology. A histopathological examination revealed that the ureteral tumor contained large atypical epithelial cells of neuroendocrine morphology without a urothelial carcinomatous component. The neoplastic cells were immunohistochemically positive for synaptophysin, chromogranin A, CD56, and cytokeratins, but they were negative for uroplakin III and thyroid transcription factor-1. The Ki-67 labeling index of the neoplastic cells was 50%. Transmission electron microscopy demonstrated the presence of numerous dense granules in the cytoplasm of the neoplastic cells. The ureteral lesion was finally classified as stage III, pT3 cN0 cM0. The patient's postoperative course was uneventful without chemoradiotherapy, and LCNEC did not recur in the subsequent nine months. This case demonstrates that LCNEC can occur in the ureter, which normally does not contain neuroendocrine cells in the urothelium.
authors.affiliation: Department of Pathology, Tokyo Medical University Hospital, Tokyo, Japan. oshiroh@yokohama-cu.ac.jp
authors.forename: Hisashi
authors.initials: H
authors.lastname: Oshiro
authors.forename: Yu
authors.initials: Y
authors.lastname: Odagaki
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Iobe
authors.forename: Chouichirou
authors.initials: C
authors.lastname: Ozu
authors.forename: Issei
authors.initials: I
authors.lastname: Takizawa
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nagai
authors.forename: Jun
authors.initials: J
authors.lastname: Matsubayashi
authors.forename: Atsushi
authors.initials: A
authors.lastname: Inagaki
authors.forename: Shinji
authors.initials: S
authors.lastname: Miyake
authors.forename: Toshitaka
authors.initials: T
authors.lastname: Nagao
mesh_terms: D000368:Aged; D018287:Carcinoma, Large Cell / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D018278:Carcinoma, Neuroendocrine / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D006801:Humans; D008297:Male; D009392:Nephrectomy; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014516:Ureteral Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D018666:Ureteroscopy
keywords: Colon cancer; immunohistochemistry; large cell neuroendocrine carcinoma; transmission electron microscopy; ureter; voided urine cytology