Intratumoral DNA stem-line heterogeneity in superficial spreading melanoma.
BACKGROUND
In primary melanomas, data on the degree of intratumoral heterogeneity to date have been lacking.


OBJECTIVE
Our purpose was to investigate intratumoral DNA stem-line heterogeneity in superficial spreading melanoma (SSM).


METHODS
Multiple measuring fields of 54 SSMs (tumor thickness median 1.60 mm) were studied by DNA image cytometry to obtain data on the number of DNA stem lines per tumor, their ploidy characteristics, and intratumoral distribution. Results were compared with standard histopathological criteria.


RESULTS
Twenty-three of 54 SSMs were found to have two or three distinct proliferating tumor cell stem lines (1.46 +/- 0.57 per tumor). Stem lines appeared spatially separated in 22 of 23 SMMs. At least 3 measuring fields per tumor were necessary to identify all stem lines with a likelihood of 95%. DNA heterogeneity correlated with tumor thickness, but occurred in 5 of 19 cases of pT1 melanoma.


CONCLUSIONS
Primary SSMs can be regarded as potentially clonally unstable with a tendency for spatial separation of tumor cell stem lines.
Helmbold
Peter
P
Department of Dermatology and Venereology, Martin Luther University Halle-Wittenberg, Halle, Saale, Germany. peter.helmbold@medizin.uni-halle.de
Altrichter
Dirk
D
Klapperstück
Thomas
T
Marsch
Wolfgang Ch
WCh
D000368:Aged; D004273:DNA, Neoplasm / Q000235:genetics*; D004171:Diploidy; D005260:Female; D006801:Humans; D008297:Male; D008545:Melanoma / Q000235:genetics* / Q000473:pathology; D008875:Middle Aged; D014411:Neoplastic Stem Cells / Q000166:cytology*; D011123:Polyploidy; D012878:Skin Neoplasms / Q000235:genetics* / Q000473:pathology
D004273:DNA, Neoplasm