Keratoacanthoma versus invasive squamous cell carcinoma: a comparison of dermatoscopic vascular features in 510 cases

Abstract

Introduction:Keratoacanthoma (KA) and invasive squamous cell carcinoma (SCC) are keratinocytic tumors displaying vascular features, imaged using dermatoscopy.Objective:Compare the dermatoscopy vascular features of KA to SCC.Methods:This prospective study examined consecutive cases of 100 KA and 410 invasive SCC in a single private practice in Sydney, Australia. Vascular features were recorded in vivo direct from patients using a non-polarized Delta 20 Heine dermatoscope. These vascular features were: linear, branching, serpentine, hairpin, glomerular and dot vessels, the presence or absence of large diameter tumor vessels, vessel presence in central verses peripheral tumor areas and tumor pink areas in different proportions. Following full excision, all cases were submitted for histopathologic diagnosis.Results:Branching vessels were the only vessel morphology that varied, with a significant incidence in KA (25.0%), compared to SCC (10.7%), P < 0.01. Large vessels were identified in 20.0% of KA, compared to 12.4% in SCC, P = 0.05. No vessels were observed in the central tumor areas in 43.4 % of KA compared to 58.0% of SCC, P = 0.01. Other data comparing the central versus peripheral tumor areas for vessels present did not reveal any distinctive associations. There were no significant differences between KA and SCC when reviewing the selected proportions of pink within the tumor.Limitations:The vascular features may be confounded by tumor depth in KA. Polarized dermatoscopy may not produce the same findings.Conclusion:This study found branching vessels to have a higher incidence in KA compared to invasive SCC. Although not statistically significant, large diameter vessels were also more frequent in KA. Proportions of pink within the tumor or central verses peripheral tumor vessel distribution were not useful diagnostic features separating KA from SCC using dermatoscopy.

Ex vivo confocal microscopy features of cutaneous squamous cell carcinoma

“…Dermoscopy has been shown to be useful for the non‐invasive diagnosis of SCC . Keratin, scale, blood spots, white circles, white structureless zones and perivascular white halos were defined as dermoscopic features of SCC, which showed a sensitivity and specificity of 79% and 87% to diagnose SCC . Among these criteria, keratin, white structureless zones, and scales were associated with well or moderately differentiated SCC.…”

“…Confocal laser scanning microscopy (CLSM) is being successfully used in the in vivo setting on a daily basis allowing the examiner to non‐invasively visualize skin lesions on a microscopic level . Recently, dermoscopic and in vivo CLSM criteria were defined for non‐invasive diagnosis of SCC, which both reached high sensitivity and specificity values and showed a good correlation with histopathology to differentiate well, moderately and poorly differentiated SCCs .…”

Autofluorescence imaging for recurrence detection in skin cancer postoperative scars

“…In addition, tumor neovascularization and elevated blood vessel permeability can lead to the loss of green autofluorescence signal due to the reabsorption and light excitation screening effects produced by blood . The arborizing vessels, at present, are identified as typical dermoscopic features for BCC , while poorly defined SCC also shows enhanced red color, numerous vessels and bleeding .…”

A Giant Keratoacanthoma Treated with Surgical Excision

“…Both keratoacanthoma and invasive SCC are common keratinocytic neoplasms. However, keratoacanthomas rarely spread via lymphatic, venous, or perineural routes [ 10 11 12 ]. It is important to note that keratoacanthoma has been found in close proximity to SCC, which suggests that a keratoacanthoma cannot be reliably distinguished from SCC on histopathologic examination [ 9 13 ].…”