title: Two histopathologic patterns of well-differentiated extraocular sebaceous carcinoma.
abstract: BACKGROUND
  No previous reports on the variation in the histopathological patterns of well-differentiated sebaceous carcinoma are yet to be published.
  
  
  METHODS
  We reviewed the histopathology of six examples of well-differentiated extraocular sebaceous carcinoma.
  
  
  RESULTS
  Two distinct histopathological patterns of sebaceous carcinoma, namely a secretory pattern (N = 2) and a non-secretory pattern (N = 4), were defined. The secretory pattern is typified by sebaceous lobular architecture with focal holocrine secretion, whereas the non-secretory pattern lacks this organoid quality. Both carcinomas with the secretory pattern showed low-grade cytological atypia, whereas the four carcinomas with the non-secretory pattern included three lesions with high-grade cytological atypia. A sebaceous adenoma-like area was seen in both secretory pattern carcinomas, whereas a focus of intraepithelial sebaceous carcinoma (sebaceous carcinoma in situ) was seen in two of the non-secretory pattern carcinomas.
  
  
  CONCLUSIONS
  The clinicopathological significance of the two histopathological patterns remains unclear, because the number of reported cases is limited. It is possible that these two histopathological patterns of carcinoma have different histogenetic and prognostic implications, but no definitive conclusions can be made until further studies of a larger number of cases can be completed.
authors.affiliation: Division of Dermatology, Department of Internal Medicine, Faculty of Medicine, Saga University, Saga, Japan. misago@post.saga-med.ac.jp
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Misago
authors.forename: Shuji
authors.initials: S
authors.lastname: Toda
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Narisawa
mesh_terms: D018266:Adenocarcinoma, Sebaceous / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D000368:Aged; D000369:Aged, 80 and over; D002278:Carcinoma in Situ / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D003537:Cystadenoma / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D005260:Female; D006258:Head and Neck Neoplasms / Q000175:diagnosis / Q000378:metabolism / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D012626:Sebaceous Gland Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery