Quantitative surface topography as a tool in the differential diagnosis between melanoma and naevus.
OBJECTIVE
The mainstays of the clinical diagnosis of melanoma are asymmetry, border irregularity, color variegation, and a diameter >6 mm, and any major progress in diagnostic accuracy will probably be related to the development of additional criteria. Such independent criteria might arise from the study of the geometry of the tumour surface, because this quality has been substantially disregarded until now. Our work is aimed at utilizing the surface topography for the differential diagnosis between malignant melanoma and naevocytic naevus.


METHODS
Dynamically focusing optical profilometry was used to measure the surfaces of negative replicas of melanocytic skin tumours and of the surrounding normal skin. 21 silicone imprints of superficial spreading melanomas and 25 imprints of naevocytic naevi were examined.


RESULTS
Melanomas and naevi differed with respect to a variety of statistical surface parameters, and a linear discriminant analysis correctly allocated 19 out of 21 melanomas (90%) and 21 out of 25 naevi (84%). To get an unbiased estimate of the errors to be expected with this classification rule, we calculated bootstrap-corrections to the apparent errors. Estimated probabilities of correct allocation were 84.1% for melanomas and 77.1% for naevi.


CONCLUSIONS
Our findings suggest that simple statistical parameters of surface topography can differentiate effectively between malignant melanomas and naevocytic naevi.
Klinik für Dermatologie und VenerologieInstitut für Mathematik, Medizinische Universität zu Lübeck, Ratzeburger Allee 160, D-23538 Lübeck, Germany.
B J
BJ
Connemann
Klinik für Dermatologie und VenerologieInstitut für Mathematik, Medizinische Universität zu Lübeck, Ratzeburger Allee 160, D-23538 Lübeck, Germany.
H
H
Busche
Klinik für Dermatologie und VenerologieInstitut für Mathematik, Medizinische Universität zu Lübeck, Ratzeburger Allee 160, D-23538 Lübeck, Germany.
J
J
Kreusch
Klinik für Dermatologie und VenerologieInstitut für Mathematik, Medizinische Universität zu Lübeck, Ratzeburger Allee 160, D-23538 Lübeck, Germany.
H M
HM
Teichert
Klinik für Dermatologie und VenerologieInstitut für Mathematik, Medizinische Universität zu Lübeck, Ratzeburger Allee 160, D-23538 Lübeck, Germany.
H H
HH
Wolff
discriminant analysis; image analysis; profilometry; roughness; skin markings