5th-WCD-Abstract-book - SebK.pdf (8.06 MB)
Dermoscopy of non-pigmented clonal seborrheic keratoses on legs
journal contribution
posted on 2018-06-18, 18:43 authored by Muntashir Shuvo, Maria Cerda, Damian Collins, Salvador J. Diaz-CanoSalvador J. Diaz-Cano, Lucia Pozo-GarciaSeborrheic keratoses (SK) are extremely
common benign epidermal lesions in adult life. Clonal seborrheic
keratosis represents an unusual histopathologic subtype of SK defined by
intraepidermal nests of basaloid cells, Borst-Jadassohn phenomenon.
This phenomenon has also been described in hidroacanthoma simplex (the
intraepidermal form of poroma) and in Bowen’s disease. Clinical and
dermoscopic diagnosis is straightforward in most cases, but clonal
seborrheic keratoses still remain a challenge.
We present five cases of non-pigmented clonal seborrheic keratoses
located on legs of adult patients. All cases were biopsied and
histologically confirmed as clonal SK. Clonal SK can occur in any body
site but in our experience, are especially common on the legs of adult
individuals. They usually present as slowly enlarging round or oval
erythematous plaques with well-defined borders and sometimes slight
superficial scale. They may simulate both non-melanocytic and
melanocytic tumors, such as superficial basal cell carcinomas,
intraepidermal squamous cell carcinomas, Spitz tumors, and malignant
melanomas.
Dermoscopy of pigmented clonal seborrheic keratoses include a globular
pattern, as the one observed in melanocytic naevi (1) or bluish ovoid
nests as described in basal cell carcinoma (2). Non-pigmented clonal SKs
show diffuse pinkish background, white network and multiple vessels
(glomerular, linear-irregular and dotted vessels) (3).
In conclusion, the slow progression of these lesions orientates to a
benign process; however, histologic confirmation is mandatory to confirm
the diagnosis and exclude skin cancer.
Bibliography:
1. Squillace L, Cappello M, Longo C, Moscarella E, Alfano R, Argenziano
G. Unusual Dermoscopic Patterns of Seborrheic Keratosis. Dermatology.
2016;232(2):198-202. PubMed PMID: 26812275.
2. Zalaudek I, Ferrara G, Argenziano G. Clonal seborrheic keratosis: a
dermoscopic
pitfall. Arch Dermatol. 2004;140(9):1169-70. PubMed PMID: 15381565.
Pubmed Central PMCID: 15381565.
3. Ramyead S, Diaz-Cano SJ, Pozo-Garcia L. Dermoscopy of clonal
seborrheic keratosis. Journal of the American Academy of Dermatology.
2015 Aug;73(2):e47-9. PubMed PMID: 26183995