title: Combined malignant melanoma and basal cell carcinoma tumor of the intermingled type.
abstract: BACKGROUND
  The combination of malignant melanoma (MM) and basal cell carcinoma (BCC) within a single tumor is an unusual finding.
  
  
  METHODS
  An 84-year-old white man with a pigmented tumor on the back showing a combination of MM and BCC.
  
  
  RESULTS
  A 1.5 x 1.5-cm irregular brown lesion on the back was clinically suggestive of MM. Histopathologically, the lesions turned out to be a combined tumor consisting of a superficial BCC and a regressive MM with a tumor thickness of 1.25 mm. The conglomerates of the BCC lay within the MM and were admixed with a high number of Melan-A-positive melanocytic cells.
  
  
  CONCLUSIONS
  By reviewing the low number of published cases, we found that a combined MM-BCC tumor exists in two variants: a collision type in which components of each cell type are clearly demarcated and an intermingled type in which both cell types grow intimately together. Although both types occur as a mere incidence, in particular, the intermingled type may be diagnostically challenging and the evaluation of its dignity may be questionable.
authors: Department of Dermatology, University Medical Center Freiburg, Freiburg, Germany. markus.braun-falco@uniklinik-freiburg.de
authors: Markus
authors: M
authors: Braun-Falco
mesh_terms: D000369:Aged, 80 and over; D002280:Basal Cell Carcinoma / Q000473:pathology* / Q000601:surgery; D006801:Humans; D008297:Male; D008545:Melanoma / Q000473:pathology* / Q000601:surgery; D009378:Neoplasms, Multiple Primary / Q000473:pathology* / Q000601:surgery; D012878:Skin Neoplasms / Q000473:pathology* / Q000601:surgery; D016896:Treatment Outcome