Clinico-pathological impact of fibroplasia in melanocytic nevi: a critical revision of 209 cases.

Fibroplasia is a peculiar stromal reaction at the base of melanocytic lesions, particularly observed in so-called dysplastic nevi. This study evaluates a series of clinico-pathological features in nevi with fibroplasia, their frequence in comparison to usual nevi, and the association of fibroplasia with the risk for the development of melanoma. A total of 209 consecutive nevi showing fibroplasia, belonging to 203 patients, was reviewed. Nevi with fibroplasia were more frequent in men, about half of the lesions belonged to patients aged 11-40 years, and the highest number (52%) were located on the posterior trunk. Lesions 6 mm or greater were 152 (72.73%). Junctional and compound nevi were 52 (24.8%), and 157 (75.2%), respectively. Inflammatory infiltrate was present in 67.8% of cases, melanophages in 56.4%, a lentiginous pattern in 31.1%, focal pagetoid infiltration in three lesions. Nevi with fibroplasia constituted 4.27% of all junctional and compound nevi diagnosed in the same period. A total of 23 patients (11.3%) had a personal history of melanoma. The total number of nevi excised from the 203 patients ranged between 1 and 21, and significantly correlated with the patient's personal history of melanoma (p < 0.001). Fibroplasia is relatively infrequent in melanocytic nevi, it does not appear related to a process of senescence of the lesion, and does not represent a particularly strong predictor of risk of melanoma.