title: Lentigo maligna - anatomic location as a potential risk factor for recurrences after non-surgical treatment.
abstract: BACKGROUND
  A higher incidence of lentigo maligna (LM) recurrences on the nose was previously observed in our cohort after non-surgical treatment.
  
  
  OBJECTIVE
  To determine histological parameters that might be related to the previously observed higher incidence of LM recurrences on the nose after non-surgical treatment.
  
  
  METHODS
  We randomly selected 22 surgical specimens of LM on the nose and 22 on the cheek. Histopathological analysis was performed on haematoxylin and eosin stained and microphthalmia transcription factor immunohistochemically stained slides. The number of pilosebaceous units (PSU) per mm, maximum depth of atypical melanocytes along the skin appendages and maximum depth of the PSU itself were determined.
  
  
  RESULTS
  The nose had a significantly higher density of PSU than the cheek. The atypical melanocytes extended deeper along the PSU on the nose with a mean (SD) depth of 1.29 mm (0.48) vs. a mean depth of 0.72 mm (0.30) on the cheek (P < 0.001). The maximum depth of the PSU on the nose was greater than on the cheek, mean (SD) depth of 2.28 mm (0.41) vs. 1.65 mm (0.82) (P = 0.003).
  
  
  CONCLUSIONS
  The higher recurrence risk of LM on the nose after non-surgical treatment that we previously observed in our cohort is most likely based on a higher density of atypical melanocytes and also their deeper extension into the follicles. These results shed more light on our previous findings and learn that anatomical location is relevant for the risk of recurrence of LM after non-surgical treatment.
authors.affiliation: Department of Dermatology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands.
authors.forename: K
authors.initials: K
authors.lastname: Greveling
authors.affiliation: Department of Pathology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands.
authors.forename: Th
authors.initials: T
authors.lastname: van der Klok
authors.affiliation: Department of Dermatology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands.
authors.forename: M B A
authors.initials: MB
authors.lastname: van Doorn
authors.affiliation: Department of Pathology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands.
authors.forename: V
authors.initials: V
authors.lastname: Noordhoek Hegt
authors.affiliation: Department of Dermatology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands.
authors.forename: E P
authors.initials: EP
authors.lastname: Prens
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002610:Cheek; D005260:Female; D018859:Hair Follicle / Q000473:pathology; D006801:Humans; D018327:Hutchinson's Melanotic Freckle / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D008297:Male; D008544:Melanocytes / Q000473:pathology; D051739:Microphthalmia-Associated Transcription Factor / Q000032:analysis*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D009666:Nose; D009669:Nose Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D012307:Risk Factors; D012627:Sebaceous Glands / Q000473:pathology; D012878:Skin Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery
chemical_list: D051739:Microphthalmia-Associated Transcription Factor