Objective: Dysplastic nevus is described as an important factor in increasing the risk of melanoma. Many authors suggested dysplastic nevi should be graded according to architectural and cytological features. Dermal fibroplasia can be in concentric or lamellar fashion. In our study we aim to grade architectural and cytological atypia in dysplastic nevi and to assess the relationship between atypia and dermal fibroplasia.

Material and Method: Ninety-three biopsies obtained from 71 patients were included in the study group. Hematoxylin-eosin stained slides were evaluated and graded according to architectural and cytological features. A total score was obtained for both architectural and cytological atypia in each case. Masson Trichrome stained sections were used to assess dermal fibroplasia and evaluated semiquantitatively.

Results: Twenty-eight (30.1%) cases had mild, 48 (51.6%) cases moderate, and 17 (18.3%) cases had severe atypia regarding architectural features. Nine (9.7%) cases were scored having mild, 28 (30.1%) cases moderate, and 56 (60.2%) cases having severe atypia regarding cytologic features. There was a significant correlation between the degree of architectural and cytologic atypia. Six (21.4%) cases with mild, 31 (64.6%) cases with moderate,, and 12 cases (70.6%) with severe architectural atypia had dermal fibroplasia. One case (11.1%) with mild, 10 cases (% 35.7) with moderate, and 10 cases (67.9%) with severe cytological atypia had dermal fibroplasia. A significant relationship was found between the presence of fibroplasia and the degree of cytological and architectural atypia.

Conclusion: A statistically significant relationship was revealed between the increase of architectural and cytological atypia and dermal fibroplasia. Detection and evaluation of stromal changes by histochemical methods, and scoring of atypia in dysplastic nevi may be helpful to distinguish dysplastic from other banal nevi.