Atypical junctional melanocytic proliferations in benign lichenoid keratosis
ABSTRACT Melanocytic lesions with lichenoid regression may mimic a benign lichenoid keratosis (BLK) histologically. A total of 336 BLKs were reviewed and deeper sections obtained to determine the frequency of this phenomenon. Two cases (0.6%) showed at least 1 melanocytic nest or junctional multinucleated melanocyte (starburst melanocyte) on deeper sections confirmed by MART-1 immunostaining. Both of these cases demonstrated solar elastosis, and 1 case had an effaced rete ridge pattern. Not included in the histological study are 5 additional cases in which the initial slide showed only lichenoid dermatitis, but deeper sections obtained before to the initial sign-out revealed a melanocytic proliferation. These 5 cases would have been signed out as "consistent with BLK" if deeper sections had not been obtained. Fluorescent in situ hybridization (FISH) was performed on 3 cases; in each case, the melanocytes demonstrated a loss of chromosome 9p21 DNA copy number. The finding of nests of genetically altered melanocytes on severely sun-damaged skin strongly suggests that these cases represent lichenoid regression of melanoma in situ. Pathologists should approach a diagnosis of BLK cautiously in the setting of severely sun-damaged skin.
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ABSTRACT: Context.-Biopsy of the face is rarely done for inflammatory skin diseases, unless the entire process is confined to the face. Objective.-We hypothesized that facial dermatitis has a differential diagnosis that is more limited than the differential diagnosis of inflammatory skin diseases that affect other parts of the body. To our knowledge, the classification of inflammatory skin diseases occurring on the face has never been conducted before in the English literature. Design.-The most-recent 100 facial biopsies of inflammatory skin conditions were retrieved from our files, and the cases were categorized into the main inflammatory skin patterns. Results.-Forty-seven cases (47%) were categorized as interface dermatitis, 2 cases (2%) as psoriasiform dermatitis, 11 cases (11%) as spongiotic dermatitis, 16 cases (16%) as diffuse and nodular dermatitis, 8 cases (8%) as perivascular dermatitis, 14 cases (14%) as folliculitis and perifolliculitis, 1 case (1%) as panniculitis, and 1 case (1%) as fibrosing dermatitis. The number of diagnostic entities represented within each of these patterns was small. Conclusions.-We believe that facial dermatitis should have its own more-circumscribed differential diagnosis. From a practical viewpoint, many of the inflammatory skin diseases that affect other parts of the body should be excluded from the differential diagnosis after the tissue is determined to be from a facial skin biopsy, and others should not be considered unless the biopsy is from the face.Archives of pathology & laboratory medicine 04/2014; 138(4):550-2. DOI:10.5858/arpa.2013-0055-OA
Journal of the American Academy of Dermatology 07/2012; 67(1):148-55. DOI:10.1016/j.jaad.2012.04.006
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ABSTRACT: This off-center fold case depicts the difficult differential diagnosis for benign lichenoid keratosis. It is challenging to diagnosis this benign lesion through clinical exam, dermoscopy, and even dermatopathology. Given its similar appearance to regressed melanoma, it is important to be cognizant of both and up to date on the dermatopathology clues.08/2011; 3(2):e25. DOI:10.4081/dr.2011.e25