Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You and Your Team.

Learn More →

Clonal Seborrheic Keratosis: A Dermoscopic Pitfall

Clonal Seborrheic Keratosis: A Dermoscopic Pitfall We congratulate Hirata and coworkers1 for their report on the dermoscopic features of 2 cases of clonal seborrheic keratosis. We would like to add some comments based on our observation of a pigmented clonal seborrheic keratosis on the leg of a 72-year-old woman. As in Hirata et al's cases, dermoscopic examination revealed large areas of a bluish pigmentation composed of multiple, variously sized and irregularly distributed, blue-gray roundish structures, also aggregated to form short lines (Figure 1). In our case, the blue-gray structures were similar to the so-called blue-gray ovoid nests, which are a dermoscopic hallmark of pigmented basal cell carcinoma.2,3 The clinical features and the additional dermoscopic observation of comedolike openings, few milialike cysts, and the jelly sign were all in favor of the diagnosis of seborrheic keratosis.3,4 However, the presence of blue-gray ovoid nests raised the need for a histopathologic examination, which revealed a clonal seborrheic keratosis. As reported by Hirata et al, the blue-gray ovoid nests corresponded histopathologically to multiple nests of pigmented basaloid cells within the epidermis (Figure 2). Figure 1. View LargeDownload Pigmented clonal seborrheic keratosis. Dermoscopically, multiple, variously sized and irregularly distributed, blue-gray roundish structures (square), also aggregated to form short lines, are seen along with multiple brown to black comedolike openings. Jelly sign (left border of the lesion) and few milialike cysts (circle) are also present. The central brown to black area corresponds to erosion covered by a scale crust (inset, clinical view; original magnification ×10). Figure 2. View LargeDownload Histopathologic features of clonal seborrheic keratosis: note the large, heavily pigmented nest of basaloid cells within the hyperplastic epidermis (circle). Some smaller, nonpigmented intraepidermal nests are discernible as well (hematoxylin-eosin, original magnification ×100). We agree with Hirata et al that, in their first case, the presence of irregular globulelike structures together with the absence of any dermoscopic features of seborrheic keratosis are in favor of the diagnosis of melanoma. However, in their second case, the differential diagnosis of pigmented basal cell carcinoma should be also considered for the presence of aggregated blue-gray structures resembling large blue-gray ovoid nests and leaflike areas. Therefore, we would suggest including pigmented basal cell carcinoma in the dermoscopic differential diagnosis of clonal seborrheic keratosis. In agreement with Hirata et al, we conclude that dermoscopy does not reach 100% diagnostic accuracy and clonal seborrheic keratosis may represent a dermoscopic pitfall, being difficult to differentiate from melanoma and basal cell carcinoma. Histopathologic examination should always be performed in cases in which dermoscopy reveals confounding features that do not allow an accurate diagnosis. The authors have no relevant financial interest in this letter. Correspondence: Dr Argenziano, Department of Dermatology, Second University of Naples, Via S Pansini 5, I-80131 Naples, Italy (argenziano@tin.it). References 1. Hirata SHAlmeida FATomimori-Yamashita J et al. "Globulelike" dermoscopic structures in pigmented seborrheic keratosis Arch Dermatol 2004;140128- 129PubMedGoogle ScholarCrossref 2. Menzies SWWesterhoff KRabinovitz HS et al. Surface microscopy of pigmented basal cell carcinoma Arch Dermatol 2000;1361012- 1016PubMedGoogle ScholarCrossref 3. Argenziano GSoyer HPChimenti S et al. Dermoscopy of pigmented skin lesions: results of a consensus meeting via the Internet J Am Acad Dermatol 2003;48679- 693PubMedGoogle ScholarCrossref 4. Braun RPRabinovitz HSKriescher J et al. Dermoscopy of pigmented seborrheic keratosis: a morphological study Arch Dermatol 2002;1381556- 1560PubMedGoogle ScholarCrossref http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Archives of Dermatology American Medical Association

Clonal Seborrheic Keratosis: A Dermoscopic Pitfall

Loading next page...
 
/lp/american-medical-association/clonal-seborrheic-keratosis-a-dermoscopic-pitfall-Qc4Aw67BRb
Publisher
American Medical Association
Copyright
Copyright © 2004 American Medical Association. All Rights Reserved.
ISSN
0003-987X
eISSN
1538-3652
DOI
10.1001/archderm.140.9.1169-b
Publisher site
See Article on Publisher Site

Abstract

We congratulate Hirata and coworkers1 for their report on the dermoscopic features of 2 cases of clonal seborrheic keratosis. We would like to add some comments based on our observation of a pigmented clonal seborrheic keratosis on the leg of a 72-year-old woman. As in Hirata et al's cases, dermoscopic examination revealed large areas of a bluish pigmentation composed of multiple, variously sized and irregularly distributed, blue-gray roundish structures, also aggregated to form short lines (Figure 1). In our case, the blue-gray structures were similar to the so-called blue-gray ovoid nests, which are a dermoscopic hallmark of pigmented basal cell carcinoma.2,3 The clinical features and the additional dermoscopic observation of comedolike openings, few milialike cysts, and the jelly sign were all in favor of the diagnosis of seborrheic keratosis.3,4 However, the presence of blue-gray ovoid nests raised the need for a histopathologic examination, which revealed a clonal seborrheic keratosis. As reported by Hirata et al, the blue-gray ovoid nests corresponded histopathologically to multiple nests of pigmented basaloid cells within the epidermis (Figure 2). Figure 1. View LargeDownload Pigmented clonal seborrheic keratosis. Dermoscopically, multiple, variously sized and irregularly distributed, blue-gray roundish structures (square), also aggregated to form short lines, are seen along with multiple brown to black comedolike openings. Jelly sign (left border of the lesion) and few milialike cysts (circle) are also present. The central brown to black area corresponds to erosion covered by a scale crust (inset, clinical view; original magnification ×10). Figure 2. View LargeDownload Histopathologic features of clonal seborrheic keratosis: note the large, heavily pigmented nest of basaloid cells within the hyperplastic epidermis (circle). Some smaller, nonpigmented intraepidermal nests are discernible as well (hematoxylin-eosin, original magnification ×100). We agree with Hirata et al that, in their first case, the presence of irregular globulelike structures together with the absence of any dermoscopic features of seborrheic keratosis are in favor of the diagnosis of melanoma. However, in their second case, the differential diagnosis of pigmented basal cell carcinoma should be also considered for the presence of aggregated blue-gray structures resembling large blue-gray ovoid nests and leaflike areas. Therefore, we would suggest including pigmented basal cell carcinoma in the dermoscopic differential diagnosis of clonal seborrheic keratosis. In agreement with Hirata et al, we conclude that dermoscopy does not reach 100% diagnostic accuracy and clonal seborrheic keratosis may represent a dermoscopic pitfall, being difficult to differentiate from melanoma and basal cell carcinoma. Histopathologic examination should always be performed in cases in which dermoscopy reveals confounding features that do not allow an accurate diagnosis. The authors have no relevant financial interest in this letter. Correspondence: Dr Argenziano, Department of Dermatology, Second University of Naples, Via S Pansini 5, I-80131 Naples, Italy (argenziano@tin.it). References 1. Hirata SHAlmeida FATomimori-Yamashita J et al. "Globulelike" dermoscopic structures in pigmented seborrheic keratosis Arch Dermatol 2004;140128- 129PubMedGoogle ScholarCrossref 2. Menzies SWWesterhoff KRabinovitz HS et al. Surface microscopy of pigmented basal cell carcinoma Arch Dermatol 2000;1361012- 1016PubMedGoogle ScholarCrossref 3. Argenziano GSoyer HPChimenti S et al. Dermoscopy of pigmented skin lesions: results of a consensus meeting via the Internet J Am Acad Dermatol 2003;48679- 693PubMedGoogle ScholarCrossref 4. Braun RPRabinovitz HSKriescher J et al. Dermoscopy of pigmented seborrheic keratosis: a morphological study Arch Dermatol 2002;1381556- 1560PubMedGoogle ScholarCrossref

Journal

Archives of DermatologyAmerican Medical Association

Published: Sep 1, 2004

Keywords: keratosis, seborrheic,dermoscopy

References