Histopathologic correlation of high-risk MelaFind TM lesions: a 3-year experience from a high-risk pigmented lesion clinic.

BACKGROUND: A significant number of pigmented lesions are biopsied to rule out melanoma, but most will be benign. MelaFindTM is a highly sensitive, noninvasive computer-assisted system to aid in clinical diagnosis of melanoma.

METHODS: A total of 140 high-risk patients were followed by one expert dermatologist. Biopsies were blindly and independently evaluated by two dermatopathologists and given histologic severity scores (HSS, 0-12) based on the histologic features of melanoma/dysplastic nevi and compared to pathologic diagnoses and MelaFindTM scores.

RESULTS: MelaFindTM reduced the biopsy number of clinically ambiguous lesions (923 scanned to 253 biopsied, 73% reduction). Biopsied cases were usually benign (135/253, 53.4%, HSS = 2.8-3.2). Dysplastic nevi with varying degrees of atypia were observed next most commonly (80/253, 31.6%, HSS = 4.7-5.2 for mild dysplasia and 7-7.6 for moderate to severe dysplasia). Melanomas comprised 11/253 (4.3%) of biopsies (HSS = 9.3-10.7). Twenty-four cases were given miscellaneous diagnoses not within the dysplastic nevus-melanoma spectrum (9.5%, HSS = 1.3). Dermal fibrosis was the most commonly identified worrisome histologic feature (177/253, 70%), closely followed by other known atypical features. Nonthreatening histologic features in benign lesions with high MelaFindTM disorganization scores were common. The HSS differed significantly depending on pathologic diagnosis severity, while the MelaFindTM score did not (benign = 2.2; mildly atypical = 4.8; moderately to severely atypical = 2.3; in-situ or invasive melanoma = 3.1).

CONCLUSIONS: MelaFindTM unequivocally reduced the number of biopsies, but banal lesions had histologic attributes resulting in high-risk MelaFindTM scores, and MelaFindTM does not correlate with degree of cytologic atypia. Knowledge of these limitations should increase bidirectional confidence when making clinicopathologic correlations in high-risk patients.