title: Consumption of the epidermis in acral lentiginous melanoma.
abstract: BACKGROUND
  Consumption of the epidermis (hereafter, consumption), namely thinning of the epidermis with attenuation of basal and suprabasal layers and loss of rete ridges adjacent to collections of melanocytes, has been used to differentiate invasive melanoma from Spitz nevi. Evaluation of 213 invasive melanomas, including only two cases of acral lentiginous melanoma (ALM), showed that the frequency of consumption increases with increasing tumor thickness.
  
  
  METHODS
  We evaluated consumption in 52 acral melanomas relative to age, gender, Breslow depth, tumor thickness (based on the 2010 American Joint Commission on Cancer guidelines), Clark level, mitoses, ulceration, vertical-growth phase, regression, tumor-infiltrating lymphocytes and anatomical site.
  
  
  RESULTS
  Consumption was more frequent in ALM with increasing Breslow depth (p = 0.01), and in the presence of ulceration (p = 0.0078); in all cases with ulcer, consumption was found adjacent to the ulceration. There was no statistically significant difference in consumption in nail melanomas in comparison to melanomas of acral skin other than the nail.
  
  
  CONCLUSIONS
  These results support the hypothesis that epidermal thinning in consumption represents an early phase of ulceration. No statistically significant difference in consumption was found between nail melanomas and melanomas of acral skin other than the nail, probably because of similar tumor thickness in both groups.
authors.affiliation: Department of Dermatology, Ikeda Municipal Hospital, Osaka, Japan Department of Pathology, Osaka Kosei-Nenkin Hospital, Osaka, Japan.
authors.forename: Chika
authors.initials: C
authors.lastname: Ohata
authors.forename: Chiaki
authors.initials: C
authors.lastname: Nakai
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Kasugai
authors.forename: Ichiro
authors.initials: I
authors.lastname: Katayama
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D004817:Epidermis / Q000473:pathology*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008545:Melanoma / Q000473:pathology*; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D018332:Nevus, Epithelioid and Spindle Cell / Q000473:pathology; D012878:Skin Neoplasms / Q000473:pathology*