BACKGROUND: Lichen planus-like keratosis (LPLK) may be difficult to differentiate from melanoma and other skin cancers on sun-damaged skin based on clinical and dermoscopic examination. Reflectance confocal microscopy (RCM) allows evaluation of skin lesions at high resolution. OBJECTIVES: The aim of this study was to identify criteria for specific diagnosis of LPLK using in vivo RCM. METHODS: Lesions included in the study were derived from patients presenting for skin examination at a private dermatology practice specializing in skin cancer. We retrospectively analysed RCM features of 28 biopsy-proven LPLK and compared them to RCM findings in skin cancers on sun-damaged skin, including five in situ squamous cell carcinomas, six actinic keratoses, seven superficial basal cell carcinomas and eight melanomas. RESULTS: The main RCM features of LPLK and their relative frequencies were: (i) typical honeycomb pattern of the spinous layer (78.6%); (ii) elongated cords and/or bulbous projections at the dermal-epidermal junction (75%); and (iii) numerous plump-bright cells and/or bright stellate spots in the superficial dermis (92.9%). These RCM features correlated with the following histopathological findings respectively: (i) spinous-granular layers without significant atypia of keratinocytes; (ii) elongated, bulbous rete ridges; and (iii) dense infiltration of melanophages and lymphocytes in superficial dermis. We propose diagnostic criteria that classify correctly 71.4% of LPLK, while avoiding misclassification of any of the skin cancers in the present series as LPLK. CONCLUSIONS: We identified RCM criteria for diagnosis of LPLK that correlate well with histopathological findings and that allow differentiation of LPLK from skin cancer.
BACKGROUND: Lichen planus-like keratosis (LPLK) may be difficult to differentiate from melanoma and other skin cancers on sun-damaged skin based on clinical and dermoscopic examination. Reflectance confocal microscopy (RCM) allows evaluation of skin lesions at high resolution. OBJECTIVES: The aim of this study was to identify criteria for specific diagnosis of LPLK using in vivo RCM. METHODS: Lesions included in the study were derived from patients presenting for skin examination at a private dermatology practice specializing in skin cancer. We retrospectively analysed RCM features of 28 biopsy-proven LPLK and compared them to RCM findings in skin cancers on sun-damaged skin, including five in situ squamous cell carcinomas, six actinic keratoses, seven superficial basal cell carcinomas and eight melanomas. RESULTS: The main RCM features of LPLK and their relative frequencies were: (i) typical honeycomb pattern of the spinous layer (78.6%); (ii) elongated cords and/or bulbous projections at the dermal-epidermal junction (75%); and (iii) numerous plump-bright cells and/or bright stellate spots in the superficial dermis (92.9%). These RCM features correlated with the following histopathological findings respectively: (i) spinous-granular layers without significant atypia of keratinocytes; (ii) elongated, bulbous rete ridges; and (iii) dense infiltration of melanophages and lymphocytes in superficial dermis. We propose diagnostic criteria that classify correctly 71.4% of LPLK, while avoiding misclassification of any of the skin cancers in the present series as LPLK. CONCLUSIONS: We identified RCM criteria for diagnosis of LPLK that correlate well with histopathological findings and that allow differentiation of LPLK from skin cancer.
Authors: Cristian Navarrete-Dechent; Antonio P DeRosa; Caterina Longo; Konstantinos Liopyris; Margaret Oliviero; Harold Rabinovitz; Ashfaq A Marghoob; Allan C Halpern; Giovanni Pellacani; Alon Scope; Manu Jain Journal: J Am Acad Dermatol Date: 2018-12-08 Impact factor: 11.527
Authors: Konstantinos Liopyris; Cristian Navarrete-Dechent; Stephen W Dusza; Ashfaq A Marghoob; Liang Deng; Barbara B Wilson; Michael A Marchetti Journal: Australas J Dermatol Date: 2018-11-18 Impact factor: 2.875
Authors: Cristián Navarrete-Dechent; Shirin Bajaj; Michael A Marchetti; Harold Rabinovitz; Stephen W Dusza; Ashfaq A Marghoob Journal: JAMA Dermatol Date: 2016-05-01 Impact factor: 10.282