Perioperative confocal microscopy of the nail matrix in the management of in situ or minimally invasive subungual melanomas.
BACKGROUND
Although dermoscopy of the nail plate is helpful to discriminate between benign and malignant causes of nail pigmentations, there remain ambiguous cases in which a matricial biopsy is required. When a subungual melanoma is diagnosed histopathologically, a complementary surgical treatment is performed secondarily, the duration of postoperative disability being accordingly prolongated.


OBJECTIVE
The purpose of our study was to evaluate the feasibility of an intraoperative diagnosis by reflectance confocal microscopy (RCM).


METHODS
Our series included nine consecutive patients who underwent a matricial biopsy for an acquired melanonychia (one benign lentigo and eight melanomas). RCM examination was performed in vivo on the nail matrix after reclination of the nail plate, and/or ex vivo on the fresh tissue biopsy. RCM data were compared with histopathology.


RESULTS
There was a good correlation between confocal and histopathological features. Seven melanoma cases were unequivocally diagnosed intraoperatively according to the confocal features, whereas the lentigo was correctly classified as a benign lesion according to RCM. The remaining lesion could not be unequivocally classified by RCM and corresponded histopathologically to an early melanoma that required immunostaining to be diagnosed.


CONCLUSIONS
Intraoperative RCM examination of the nail matrix is an efficient diagnostic approach of melanonychia striata that permits an extemporaneous diagnosis of malignancy and therefore a one-step surgical treatment of in situ or minimally invasive melanoma, reducing dramatically the duration of postoperative disability.
Department of Dermatology, Lyon 1 University, Hospices Civils de Lyon, Centre Hospitalier Lyon Sud, 69495 Pierre Bénite CEDEX, France. sebastien.debarbieux@chu-lyon.fr
S
S
Debarbieux
V
V
Hospod
L
L
Depaepe
B
B
Balme
N
N
Poulalhon
L
L
Thomas
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D046169:Dermoscopy / Q000379:methods; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007911:Lentigo / Q000175:diagnosis / Q000601:surgery; D008297:Male; D008545:Melanoma / Q000175:diagnosis* / Q000601:surgery; D018613:Microscopy, Confocal / Q000379:methods; D008875:Middle Aged; D009260:Nail Diseases / Q000473:pathology / Q000601:surgery*; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000601:surgery; D016896:Treatment Outcome