Clinical and immunohistochemical analysis of the verrucous and non-verrucous divided nevus of the eyelids.

Purpose: Divided nevus with verrucous hyperplasia will always recur after surgery but non-verrucous divided eyelid nevus rarely recur. This study analyzed the differential expression of Ki-67, S100, Melan A and HMB45 and identified the correlation between the clinical and histopathological features of verrucous and non-verrucous divided eyelid nevus.

Methods: This study included 29 patients, of whom 8 patients had verrucous divided nevus. Immunohistochemistry labeling was used to assess the expression of Ki-67, S100, Melan A and HMB45 after excision. The difference between verrucous and non-verrucous divided eyelid nevus was analyzed.

Results: The patients' ages ranged from 2 to 59 years, with a mean age of 19 years. The lesion size ranged from 1.5 to 2.0 cm in diameter and invaded the eyelid margins and the posterior lamella of the eyelids. Immunohistochemistry labeling showed strong positivity for approximately 98.5% of S100 and positive staining for approximately 27.6% of Ki-67, 72.4% of Melan A and 6.8% of HMB45. However, Ki-67 was significantly upregulated in verrucous divided nevus of the eyelids compared with non-verrucous divided nevus, with approximately 38.8% upregulation in verrucous and 18.3% upregulation in non-verrucous nevus.

Conclusions: This study correlated the clinic-pathologic features of verrucous divided eyelid nevus by means of statistically analyzing the varied clinical features and pathological impressions. The significant over-expression of S100 may be used as an indicator of divided nevus of the eyelids, and the over-expressed Ki-67 may contribute to the recurrence of verrucous divided nevus. High expression of HMB45 and Melan A may represent malignant transformation.