1. Histomorphologic assessment and interobserver diagnostic reproducibility of atypical spitzoid melanocytic neoplasms with long-term follow-up.
- Author
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Gerami P, Busam K, Cochran A, Cook MG, Duncan LM, Elder DE, Fullen DR, Guitart J, LeBoit PE, Mihm MC Jr, Prieto VG, Rabkin MS, Scolyer RA, Xu X, Yun SJ, Obregon R, Yazdan P, Cooper C, Weitner BB, Rademaker A, and Barnhill RL
- Subjects
- Adult, Australia, Child, Consensus, Epidermis pathology, Female, Follow-Up Studies, Humans, Male, Mitosis, Mitotic Index, Neoplasm Grading, Observer Variation, Predictive Value of Tests, Prognosis, Reproducibility of Results, Skin Ulcer pathology, Time Factors, United States, Young Adult, Melanocytes pathology, Melanoma pathology, Nevus, Epithelioid and Spindle Cell pathology, Skin Neoplasms pathology
- Abstract
Predicting clinical behavior of atypical Spitz tumors remains problematic. In this study, we assessed interobserver agreement of diagnosis by 13 expert dermatopathologists for atypical Spitz tumors (n=75). We determined which histomorphologic features were most heavily weighted for their diagnostic significance by the experts and also which histomorphologic features had a statistically significant correlation with clinical outcome. There was a low interobserver agreement among the experts in categorizing lesions as malignant versus nonmalignant (κ=0.30). The histomorphologic features that were given the most diagnostic significance by the experts were: consumption of the epidermis, atypical mitoses, high-grade cytologic atypia, and mitotic rate. Conversely, the histomorphologic features that most correlated with disease progression were: frequent mitoses, deep mitoses, asymmetry, high-grade cytologic atypia, and ulceration. The presence and/or pattern of pagetoid spread, consumption of the epidermis, and lymphoid aggregates demonstrated no association with clinical behavior. The results support the assertion that there is a lack of consensus in the assessment of atypical Spitz tumors by expert dermatopathologists. Importantly, many features used to distinguish conventional melanoma from nevi were not useful in predicting the behavior of atypical Spitz tumors. This study may provide some guidance regarding histologic assessment of these enigmatic tumors.
- Published
- 2014
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