Evaluation of the grade of cytologic atypia in dysplastic nevi and it?s relationship with dermal fibroplasia

Aim and hypothesis: The exact cause of melanoma is unknown, despite many studies showed the existence of melanocytic dysplastic nevi as an important factor in increasing the risk of melanoma. İnvestigators suggested that dysplastic nevi should be graded with architectural and cytologic features. Generally there is a significant correlation between architectural and cytologic degree in different groups of patients.Dermal fibroplasia in DN can be in concentric or lamellar form. In our study we aim to describe architectural and cytologic degree of atypia and to evaluate the relationship between this atypia and dermalfibroplasiaMaterials and methods: Ninety three biopsies obtained from 71 patient who were diagnosed between 2003-2008 as dysplastic nevi are included in this study. Four ?m thick H&E stained slides were prepared from paraffin blocks were evaluated by light microscopy and were graded according to architectural and cytologic features. In this grading the following features were recorded in the presence or absence of intraepidermal or junctional component. (1) Architecture: circumscription, symmetry, cohesiveness of nests, suprabasal melanocytes, confluence, and single-cell proliferation; (2) Cytology of melanocytes: round/euchromatic nuclei, nuclear enlargement, cell enlargement, and prominent nucleoli. Each criterion was given a value of 0 or 1, and a summation score was obtained for both architecture and cytology in each case. Masson Trichrome stain has been applied to the tissue sections and a semiquantitative evaluation of fibroplasia was performed and scored as positive (1) or negative (0).Results: The study included 71 patients from the ages at diagnosis ranged from 12 to 75 years, and median is 33.62 . Of the cases, 32 (45.1 %) were female patients, while 39 (54.9 %) were male. Lesions are composed of 93 nevi of 71 patients ( 33 junctional and 60 compound nevi).The cases of 28 patients by the degree of architectural atypia (30.1%) mild, 48 cases (51.6%) moderate and 17 cases (18.3%) were scored as severe architectural atypia. The degree of cytologic atypia in 9 cases (9.7%) mild, 28 cases (30.1%) moderate and 56 cases (60.2%) severely atypical cytologic features. There was a significant correlation between the degree of architectural and cytological atypia (r = 0.084). Slight architectural atypia in 6 cases (21.4%), moderate architectural atypia 31 cases (64.6%), severe architectural atypia in 12 cases (70.6%), mild cytologic atypia 1 case (11.1%), moderate cytologic atypia 10 cases (% 35.7) and severe cytologic atypia 10 cases (67.9%) had dermal fibroplasia. A significant relationship was found between the presence of fibroplasia and the degree of cytologic and architectural atypia.Conclusion: Dysplastic nevi is characterized by architectural and cytological atypia histologicaly and because of this features, morphologically and biologically they are between the common melanocytic nevi and melanoma. As the architectural and cytological atypia degree increases in dysplastic nevi in our study, we found a significant increase in the presence of dermal fibroplasia. Detection and grading of stromal changes in dysplastic nevi by histo-chemical methods, may be helpful to distinguish DN?s from other banal nevi.