To the Editor: The cost, morbidity, and mortality associated with melanoma underscores the importance of accurate diagnosis, but previous studies have suggested high levels of diagnostic discordance among pathologists in the interpretation of melanocytic lesions.1Shoo B.A. Sagebiel R.W. Kashani-Sabet M. Discordance in the histopathologic diagnosis of melanoma at a melanoma referral center.J Am Acad Dermatol. 2010; 62: 751-756Abstract Full Text Full Text PDF PubMed Scopus (155) Google Scholar, 2Hawryluk E.B. Sober A.J. Piris A. et al.Histologically challenging melanocytic tumors referred to a tertiary care pigmented lesion clinic.J Am Acad Dermatol. 2012; 67: 727-735Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar, 3Corona R. Mele A. Amini M. et al.Interobserver variability on the histopathologic diagnosis of cutaneous melanoma and other pigmented skin lesions.J Clin Oncol. 1996; 14: 1218-1223Crossref PubMed Scopus (188) Google Scholar, 4Eriksson H. Frohm-Nilsson M. Hedblad M.A. et al.Interobserver variability of histopathological prognostic parameters in cutaneous malignant melanoma: impact on patient management.Acta Derm Venereol. 2013; 93: 411-416Crossref PubMed Scopus (14) Google Scholar, 5Patrawala S. Maley A. Greskovich C. et al.Discordance of histopathologic parameters in cutaneous melanoma: clinical implications.J Am Acad Dermatol. 2016; 74: 75-80Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar We sought to evaluate the degree of concordance between the submitted diagnoses and second-level review of 154 biopsies from patients referred from the community for treatment of melanoma to the Medical University of South Carolina during January 2016-June 2017. The rate of discrepancy between outside and internal reports was 38.3% (59/154) over the 18 months studied. There was a complete change of diagnosis in 8 patients (5.2%), a clinically significant downgrade in the diagnosis of 33 patients (21.4%), and a clinically significant upgrade in the diagnosis of 25 patients (16.2%). Changes were considered significant if they affected staging or management. The reported depth changed in 43 cases (27.9%), and the stage changed in 23 cases (14.9%). The changes in diagnosis are summarized in Table I.Table IComplete changes in diagnosis among patients referred to Medical University of South Carolina for melanoma treatmentChange in diagnosisValue, N = 154, N (%)MIS → AK1MIS → Clark nevus2MIS → AMP1AMP → MIS1AMP → invasive melanoma1Invasive melanoma → Clark nevus2Total8 (5.2)AK, Actinic keratotis; AMP, atypical melanocytic proliferation; MIS, melanoma in situ. Open table in a new tab AK, Actinic keratotis; AMP, atypical melanocytic proliferation; MIS, melanoma in situ. Shoo et al1Shoo B.A. Sagebiel R.W. Kashani-Sabet M. Discordance in the histopathologic diagnosis of melanoma at a melanoma referral center.J Am Acad Dermatol. 2010; 62: 751-756Abstract Full Text Full Text PDF PubMed Scopus (155) Google Scholar reported a diagnostic discordance rate of 14.3% and Hawryluk et al2Hawryluk E.B. Sober A.J. Piris A. et al.Histologically challenging melanocytic tumors referred to a tertiary care pigmented lesion clinic.J Am Acad Dermatol. 2012; 67: 727-735Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar 35%, resulting in a change of therapy for 13% of patients. Ours was a retrospective study limited to an 18-month period at a single institution, but our results suggest that discordance between pathologists regarding the diagnosis and the prognostic attributes of melanocytic lesions occurs in a substantial proportion of cases and represents an important practice gap and a source of patient, provider, and community dissatisfaction in pathologists. A limitation of our study is the lack of a gold standard for melanoma diagnosis; diagnoses remain subjective.