A 79-year-old woman is seen in the clinic for treatment of a lesion on her leg that has been gradually increasing in size over the past several months. The patient has a history of actinic keratosis of the face and hand, as well as a squamous cell carcinoma in situ that was removed from her forehead. The lesion in question is asymptomatic and has not bled. Examination reveals a 1.0-cm erythematous scaling plaque on her right anterior thigh. Multiple lentigines and actinic keratoses are noted on her hands and face.
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Lichenoid keratosis, occasionally referred to as lichen planus-like keratosis, typically is seen as an isolated raised plaque that ranges in color from pink to brown to gray.1 Less common is the appearance of multiple lesions.1 The condition occurs in older adults, often on the extremities or trunks. Individuals with fair skin and ample past sun exposure are most susceptible. The condition was first described in 1966 by 2 independent dermatopathology groups and is believed to represent an inflamed, regressing variant of a solar lentigo or seborrheic keratosis.2-4
Lichenoid keratosis may mimic basal cell carcinomas clinically.4 Dermoscopy may be useful in differentiating this benign neoplasm from melanoma; however, definitive diagnosis requires histopathologic examination.5 Treatment is readily accomplished with liquid nitrogen cryosurgery or curettage.
Stephen Schleicher, MD, is director of the DermDox Center for Dermatology, associate professor of medicine at Commonwealth Medical College, and clinical instructor of dermatology at Arcadia University and Kings College.
1. Abdulla FR, Mutasim DF. Multiple benign lichenoid keratoses. J Am Acad Dermatol. 2010;62(5):900-901.
2. Lumpkin LR, Helwig EB. Solitary lichen planus. Arch Dermatol. 1966;93(1):54-55.
3. Shapiro L, Ackerman AB. Solitary lichen planus-like keratosis. Dermatologica. 1966;132(5):386-392.
4. Kulberg A, Weyers W. Regressing basal-cell carcinoma masquerading as benign lichenoid keratosis. Dermatol Pract Concept. 2016;6(4):13-18.
5. Gori A, Oranges T, Janowska A, et al. Clinical and dermoscopic features of lichenoid keratosis: a retrospective case study. J Cutan Med Surg. 2018;22(6):561-566