The 81-year-old woman presents for her annual skin examination. Her medical history is positive for actinic and seborrheic keratosis and negative for skin cancer. She admits a history of ample sun exposure. Her main complaint is a relatively new growth on her upper chest. On physical examination, a 1.5-cm slightly violaceous plaque is noted; numerous keratoses and lentigo lesions are visible elsewhere on her chest.
Lichen planus-like keratosis (LPLK) presents as a pink, violaceous, light brown, or grey solitary macule, papule, or plaque. Lesions arise acutely and may begin as an erythematous patch. Older lesions manifest varying degrees of hyperpigmentation. The plaques range in size...
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Lichen planus-like keratosis (LPLK) presents as a pink, violaceous, light brown, or grey solitary macule, papule, or plaque. Lesions arise acutely and may begin as an erythematous patch. Older lesions manifest varying degrees of hyperpigmentation. The plaques range in size from 0.5 cm to 2 cm.1 Location of LPLK favors sites that are prone to receiving ample sun exposure such as the arms, face, and sternum. Lesions most commonly occur in middle-aged to older women. The etiology is uncertain; LPLK may evolve from a seborrheic keratosis or solar lentigo undergoing an inflammatory response.2
Dermoscopy of LPLK is nondiagnostic, revealing either localized or diffuse granularity.3,4 Definitive diagnosis is made histologically with the finding of a dense lichenoid inflammatory infiltrate that often obscures the dermoepidermal junction.5.6 Biopsy is prudent to rule out more serious pathologies such as Bowen disease, basal cell carcinoma, and melanoma. Shave excision of the lesions is usually curative and provides a specimen for histology.
Stephen Schleicher, MD, is director of the DermDox Dermatology Centers, associate professor of medicine at Geisinger 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. doi:10.1016/j.jaad.2009.05.020.
2. Bugatti L, Filosa G. Dermoscopy of lichen planus-like keratosis: a model of inflammatory regression. J Eur Acad Dermatol Venereol. 2007;21(10):1392-1397. doi:10.1111/j.1468-3083.2007.02296.x
3. Zaballos P, Blazquez S, Puig S, et al. Dermoscopic pattern of intermediate stage in seborrhoeic keratosis regressing to lichenoid keratosis: report of 24 cases. Br J Dermatol. 2007;157(2):266-272. doi:10.1111/j.1365-2133.2007.07963.x
4. Liopyris K, Navarrete-Dechent C, Dusza SW, et al. Clinical and dermoscopic features associated with lichen planus-like keratoses that undergo skin biopsy: a single-center, observational study. Australas J Dermatol. 2019;60(2):e119-e126. doi: 10.1111/ajd.12955
5. Morgan MB, Stevens GL, Switlyk S. Benign lichenoid keratosis: a clinical and pathologic reappraisal of 1040 cases. Am J Dermatopathol. 2005;27(5):387-392. Doi: 10.1097/01.dad.0000175533.65486.84
6. Vincek V. Lichen planus-like keratosis: clinicopathological evaluation of 1366 cases. Int J Dermatol. 2019;58(7):830-833. doi:10.1111/ijd.14358
This article originally appeared on Clinical Advisor