Dermoscopy as a Tool in Differentiating Cutaneous Squamous Cell Carcinoma From Its Variants

Abstract

Background: Dermoscopic features of cutaneous squamous cell carcinoma (cSCC) have been widely studied, but their accuracy should be further investigated.
 Objectives: This study assessed the diagnostic accuracy of a set of predetermined dermoscopic structures for 3 variants of cSCC, namely Bowen disease, keratoacanthoma and invasive cSCC.
 Methods: Dermoscopic images of 56 histopathologically confirmed cSCC lesions (9 Bowen disease lesions, 7 keratoacanthomas, and 40 invasive cSCCs) were examined, and the diagnostic accuracy of dermoscopic structures was assessed. Discriminative ability of statistically significant positive predictors was determined using receiver operating characteristic (ROC) curves, and defined as an area under the ROC curve >0.700.
 Results: Dermoscopic structures with statistical significance and discriminative ability were: for Bowen disease, clustered glomerular vessels and erosions; for keratoacanthoma, a central keratin plug; and for invasive cSCC, a mixed color of the background. Clustered and glomerular vessels had, for Bowen disease, perfect diagnostic accuracy, with: sensitivity of 88.9% for both features; specificity of 97.9% and 93.6%, respectively; positive predictive value (PPV) of 88.9% and 72.7%, respectively; and negative predictive value (NPV) of 97.8% for both. Erosions had, for BD, high specificity (87.2%) and NPV (91.1%), but low sensitivity (55.6%) and PPV (45.5%). A central keratin plug had, for keratoacanthoma, high specificity (87.8%) and NPV (93.5%), but low sensitivity (57.1%) and PPV (40%). A mixed background color had, for invasive cSCC, high specificity (81.3%) and PPV (89.7%), but low sensitivity (65%) and NPV (48.2%).
 Conclusion: Dermoscopy accurately differentiates BD, through clustered glomerular vessels, from keratoacanthoma and invasive cSCC. Dermoscopic structures of keratoacanthoma and invasive cSCC overlap, and only histopathologic analysis differentiates them precisely.

Dermoscopy of Non-Melanocytic Skin Tumors: A Descriptive Study in a Tertiary Care Hospital

“…ern and ulcera# ons are features of poorly diff eren# ated invasive SCC. 14 In our study we found white structureless area with polymorphous vessels and ulcera# ons in SCC similar to a study quoted in the literature. Diff eren# a# ng SCC and keratoacanthoma dermoscopic features overlap therefore histopathology should be considered, our study being cross sec• onal, we were not able to followup the pa• ents.…”

Dermoscopic findings in two cases of keratoacanthoma en plaque

“…Although a hairpin vessel is one of the dermoscopic criteria for keratoacanthoma, a radiating appearance may be a characteristic of keratoacanthoma en plaque. 3 Histopathologically, dilated vessels were seen in the periphery of the lesion, whereas in both cases the central area did not include dilated vessels. In a previously reported case, although irregular vessels were observed, there were no surrounding radiating hairpin vessels.…”

Race-Specific and Skin of Color Dermatoscopic Characteristics of Skin Cancer: A Literature Review

“…In general, the discrimination of a keratoacanthoma and a well-differentiated SCC on the clinical and dermatoscopic basis is very challenging. However, it has been suggested that the presence of keratin and white background color may indicate keratoacanthoma, whilst mixed color favors an invasive cSCC [ 21 ]. Poorly differentiated SCCs are dermatoscopically characterized by a predominant red color, resulting from the presence of dense neo-vascularization and/or hemorrhage [ 19 ].…”