A 62-year-old woman seeks consultation for a nonhealing lesion above her upper lip that has increased in size gradually over the past few months. Her medical history is positive for basal cell carcinoma of the right nares treated recently with radiation therapy. She is fair-skinned and quit smoking 5 years previously. Examination of the affected site reveals a crusted plaque with a somewhat indurated and erythematous base.
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Biopsy of the lesion was performed and revealed lichenoid actinic keratosis. Lichenoid actinic keratoses are a subset of actinic keratosis that includes atrophic, bowenoid, acantholytic, pigmented, and hypertrophic variants.1 The first 5 cases were described in 1967, and all lesions presented as elevated papules with irregular borders and surrounding inflammation.2
The differential diagnosis should include squamous cell carcinoma and lichen planus-like keratosis. Lichen planus-like keratosis presents as reddened to violaceous papular lesions. It most commonly occurs in middle-aged white women and appears on the distal forearms, hands, and chest.3
Because a small percentage of actinic keratoses may eventually develop into squamous cell carcinoma, treatment is warranted.4 Therapy is lesion-directed and includes surgical or cryosurgical procedures as well as topical agents such as 5-fluorouracil, imiquimod (2.5%, 3.75%, and 5% formulations), diclofenac 3%, aminolevulinic acid (photodynamic therapy), and ingenol mebutate gel.5
Stephen Schleicher, MD, is an associate professor of medicine at the Commonwealth Medical College in Scranton, Pennsylvania, and an adjunct assistant professor of dermatology at the Perelman School of Medicine at the University of Pennsylvania in Philadelphia. He practices dermatology in Hazleton, Pennsylvania.
- Weedon D. Tumors of the epidermis. Actinic keratosis. In: Weedon D. Weedon’s Skin Pathology. 3rd ed. London, UK: Churchill Livingstone/Elsevier; 2010:676-679.
- Hirsch P, Marmelzat WL. Lichenoid actinic keratosis. Dermatol Int. 1967;6:101-103.
- Laur WE, Posey RE, Waller JD. Lichen planus-like keratosis. A clinicohistopathologic correlation. J Am Acad Dermatol. 1981;4:329-336.
- Stockfleth E. The paradigm shift in treating actinic keratoses: a comprehensive strategy. J Drugs Dermatol. 2012;11:1462-1467.
- Samrao A, Cockerell CJ. Pharmacotherapeutic management of actinic keratosis: focus on newer topical agents. Am J Clin Dermatol. 2013;14:273-277.