A Clinicopathological Study of Lichen Planus-like Keratosis / 대한피부과학회지

ABSTRACT

Background@#Lichen planus-like keratosis (LPLK), also known as benign lichenoid keratosis, usually presents as a single, brown to red, scaly, flat-topped plaque. Several large-scale studies have reported LPLK in Caucasians; however, no study has reported LPLK in Koreans. @*Objective@#To investigate the clinicopathological features of LPLK in Koreans. @*Methods@#We retrospectively investigated 60 patients with LPLK at Yeungnam University Hospital between 2001 and 2019. Diagnosis of LPLK was confirmed by histopathological examination in all patients. @*Results@#Most patients (96.6%) had a single lesion. The most common location was the face (63.3%), followed by the trunk (16.7%), and upper extremities (11.7%). Mean patient age was 62.7 years, and the femalemale ratio was 1.31. The initial clinical impression involved seborrheic keratosis in 56.7% of cases and LPLK in only 16.7% of cases. Solar elastosis (58.3%) and red blood cell extravasation (55%) were also commonly observed in this study population. Histopathological findings revealed focal parakeratosis (35%), dermal eosinophils (30%), and plasma cells (10%). @*Conclusion@#LPLK may commonly be misdiagnosed, because it is often clinically indistinguishable from seborrheic keratosis and other epithelial neoplasms. Skin biopsy findings and clinicopathological correlation are therefore necessary for differential diagnosis. Several histopathological features, such as parakeratosis as well as dermal eosinophil and plasma cell infiltration, can distinguish LPLK from lichen planus.