Preoperative ultrasonic assessment of thin melanocytic skin lesions using a 100-MHz ultrasound transducer: a comparative study.
BACKGROUND
It has been shown that tumor thickness (TT) of melanocytic skin lesions (MSL) of less than 1 mm vertical thickness assessed by 20 MHz are often incorrectly evaluated.


OBJECTIVE
We aimed to evaluate the accuracy of 100-MHz ultrasound for the determination of TT of thin MSL, compared with conventional 20-MHz ultrasound and histologic findings.


METHODS
Thirty-seven patients with 50 suspicious MSL, including tumor diameter up to 1 cm and maximum vertical TT of less than 1 mm, were recruited. The agreement between the histologically and ultrasographically measured TT was analyzed using Bland and Altman plots.


RESULTS
Compared to histology, 20-MHz ultrasound (33.9 microm) as well as 100-MHz (16 microm) resulted in overestimation of TT that was twofold higher for 20-MHz ultrasound. The latter also revealed wider 95% limits of agreement (4.9 to 63 microm) than 100-MHz ultrasound (3.5 to 28.7 microm).


CONCLUSIONS
Analysis of agreement clearly demonstrated that the performance of 100-MHz ultrasound is superior to conventional 20-MHz ultrasound, even though a relatively small positive bias was observed in 100-MHz ultrasound, indicating a systematic error. We consider 100-MHz ultrasound a useful tool for the noninvasive determination of TT of thin MSL in vivo.
Gambichler
Thilo
T
Department of Dermatology, Ruhr-University Bochum, Bochum, Germany. t.gambichler@klinikum-bochum.de
Moussa
Georg
G
Bahrenberg
Katharina
K
Vogt
Michael
M
Ermert
Helmut
H
Weyhe
Dirk
D
Altmeyer
Peter
P
Hoffmann
Klaus
K
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging* / Q000473:pathology*; D008875:Middle Aged; D009506:Nevus / Q000000981:diagnostic imaging* / Q000473:pathology*; D011300:Preoperative Care / Q000295:instrumentation* / Q000379:methods; D011446:Prospective Studies; D012878:Skin Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D014159:Transducers; D014463:Ultrasonography