Can Ki-67 immunohistochemistry marker differentiate mycosis fungoides from cutaneous lichen planus?

Abstract

Objective: The purpose of this study was to evaluate the immunohistochemical expression of Ki-67 marker in MF and LP lesions. Methods: This cross-sectional analytical study included patients undergoing skin biopsy with their first clinical and pathologic diagnosis of MF and cutaneous LP by Ki-67 immunohistochemistry (IHC). Sixty-two patients with cutaneous LP and MF were studied in two groups of 39 and 23 patients, respectively. Linear regression was used for the possible correlation between age and Ki-67 index (%) in both LP and MF patients. Results: The results of this study found that Ki-67 was expressed in 100% of both MF and LP lesions, and no significant correlation was found between Ki-67 and either of the two types of diseases (p = 0.606). The results of this study also showed that expression of Ki-67 marker was more than 25% in both types of diseases in 70% of the population, which seems not to be directly related to malignancy. Conclusions: IHC with proliferative marker Ki-67 is not a valuable technique for differentiating cutaneous LP from MF lesions alone.