Pigmented eccrine Poroma: dermoscopic and confocal features

Abstract

Eccrine poroma is a rare benign adnexal tumor of epithelial cells originating from the terminal ductal portion of the sweat glands that is typically located on palms and soles, although other cutaneous sites can be affected [1]. It is usually nonpigmented even if there is a pigmented variant that corresponds to 17% of cases and it is usually underdiagnosed, since it is mistakenly confused with other pigmented tumors [2,3]. Dermoscopy and reflectance confocal microscopy (RCM) may assist in the correct diagnosis of this tumor.Herein, we report one case of pigmented eccrine poroma (PEP) that simulated clinically a cutaneous melanoma or a basal cell carcinoma. Dermoscopy and RCM excluded the possibilities of those two diagnoses; the overall confocal findings were suggestive for a benign epithelial tumor. Histology was fundamental to diagnose this lesion as a pigmented eccrine poroma. Even if the diagnosis of eccrine poroma remains histopathological still, as in this case report, noninvasive tools such as dermoscopy and RCM examinations can be of help to rule out the diagnosis of melanoma. Larger studies on this rare pigmented variant of eccrine poroma could shed new light on the identification of specific diagnostic dermoscopic and confocal features.

Dermoscopic features and patterns of poromas: a multicentre observational case–control study conducted by the International Dermoscopy Society

“…Lesion morphology (macule, papule, plaque, nodule, tumour), number of colours and maximum diameter (in millimetres) were recorded. A comprehensive list of dermoscopic structures reported to be present in poromas was created (Data , Supporting Information) . After careful appraisal of previous descriptions and consensus amongst the reviewers, cherry‐blossom vessels, flower‐like vessels, floral vessels, chalice‐like vessels and leaf‐like vessels were categorized as structure called branched vessels with rounded endings, defined as branched vessels with looped or coiled terminal endings that characteristically have a rounded silhouette.…”

“…A comprehensive list of dermoscopic structures reported to be present in poromas was created (Data S1, Supporting Information). [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] After careful appraisal of previous descriptions and consensus amongst the reviewers, cherry-blossom vessels, flower-like vessels, floral vessels, chalice-like vessels and leaf-like vessels were categorized as structure called branched vessels with rounded endings, defined as branched vessels with looped or coiled terminal endings that characteristically have a rounded silhouette. We considered milky-red areas, pink-white structureless areas, pink homogeneous area and creamy red background as one feature called milky-red areas, defined as structureless areas with pink to white-red areas.…”

Eccrine poroma of the nipple: the first reported case

“…Eccrine poroma was first described in 1956 1. It is a rare benign adnexal tumour which arises from sweat glands of eccrine origin.…”

Epidermoid Cyst versus Basal Cell Carcinoma by Dermoscopy

“…Dermoscopy is a simple and noninvasive method to diagnose different skin conditions. Dermoscopic features of Epidermal Cyst are the comedos (sometime too small to be recognized by the naked eye) and the absence of other criteria for BCC-arborising vessels and large ovoid nests [1,2] .…”