title: Submucosal tumor extension in hypopharyngeal cancer.
abstract: OBJECTIVE
  To study the incidence and extent of submucosal tumor extension in hypopharyngeal cancer and to evaluate the impact on the tumor recurrence and overall survival rates.
  
  
  METHODS
  Fifty-seven resected specimens of hypopharyngeal cancer were studied in detail from January 1986 to December 1989 by use of the whole-organ, step-serial sectioning technique.
  
  
  RESULTS
  Three types of submucosal tumor extension could be identified. Type I extension was characterized by a tumor with a smooth round contour that extended submucosally. The mucosa was thereby elevated and was detectable on gross inspection at operation. In type II extension, tongues and islands of tumor infiltrated within the submucosa, and these were not noticeable on gross examination. Skip metastasis in the submucosa where the submucosal tumor was completely separated from the main tumor bulk was classified as type III extension. Thirty-three patients (58%) had submucosal tumor extension. The frequencies (and extents of submucosal tumor extension) in the superior, medial, lateral, and inferior directions were 16% (3-10 mm), 37% (2-37 mm), 26% (2-37 mm), and 28% (3-35 mm), respectively. Two thirds of the submucosal extension was type I (22 of 33), and only 1 patient had a true skip lesion submucosally (type III extension). Type II submucosal extension was found in one third of the patients (11 of 33). This occurred significantly more often in the patients who had received radiotherapy before surgery (82% [9/11]; P < .001; 95% confidence interval, 1.28-4.44). The presence of submucosal tumor extension had no effect on the tumor recurrence and overall survival rates.
  
  
  CONCLUSIONS
  The incidence of submucosal tumor extensions in hypopharyngeal cancer is high (58%), but most (67%) of them can be detected grossly at operation. The presence of submucosal tumor extension does not adversely affect the survival and tumor recurrence rates.
authors.affiliation: Department of Surgery, Kwong Woh Hospital, Hong Kong, People's Republic of China.
authors.forename: C M
authors.initials: CM
authors.lastname: Ho
authors.forename: W F
authors.initials: WF
authors.lastname: Ng
authors.forename: K H
authors.initials: KH
authors.lastname: Lam
authors.forename: W J
authors.initials: WJ
authors.lastname: Wei
authors.forename: A P
authors.initials: AP
authors.lastname: Yuen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016001:Confidence Intervals; D004947:Esophagus / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007012:Hypopharyngeal Neoplasms / Q000145:classification / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery; D015994:Incidence; D008198:Lymph Nodes / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009092:Mucous Membrane / Q000473:pathology; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D009367:Neoplasm Staging; D009960:Oropharynx / Q000473:pathology; D011300:Preoperative Care; D015996:Survival Rate