Background:Cutaneous horns usually develop on a keratinocytic base with the histopathology on a spectrum ranging from benign keratosis through to invasive squamous cell carcinoma (SCC). Some features of horns are easily identified using dermatoscopy.Objective:To investigate if specific clinical or dermatoscopy features of horns correlate with the histopathology in the base of the horn.Methods:Consecutive horn cases (n=163) were assessed prospectively in vivo for horn height, terrace morphology and base erythema using a Heine Delta 20 dermatoscope. Cases with potentially confounding influences were excluded. A history of horn pain or pain on palpation was also recorded.Results:Benign keratosis (n = 49), actinic keratosis (n = 21), SCC in situ (n = 37) and invasive SCC (n = 56) were recorded. An invasive SCC presenting as a horn as most likely to have a height less than the base diameter, 66% (37/56). Compared to the other study entities, invasive SCC tends to have less terrace morphology (P<0.05), a higher incidence of base erythema (P<0.05) and more pain (P<0.01).Limitations:Data categories did not include anatomic site or horn growth rates. Excision selection bias favored the incidence of invasive SCC.Conclusions:Horns presenting on an invasive SCC base are more likely to have a height less than the diameter of the base, not to have terrace morphology, to have an erythematous base and to be painful.

Objective:Compare the dermatoscopy vascular features of well differentiated with non-well differentiated squamous cell carcinoma (SCC).Design:A prospective study of 294 consecutive cases of histopathologically confirmed invasive SCC compared the dermatoscopic vascular features of well to combined moderate and poorly differentiated tumors. These features were recorded live directly from the patients and included: the percentage of pink in the tumor, the presence of branching, serpentine, dot, hairpin, glomerular and linear vessels, and the number of these vessel types present within each tumor. Vessel types were also reviewed by tumor depth in 1 mm increments.Setting:Two medical practices in Sydney, Australia.Patients:Eighty-six female and 208 male patients (29–95 years old).Main outcome measure:Dermatoscopic vascular feature variation between grades of tumor differentiation and tumor depth.Results:Of 294 invasive SCCs, 255 (87%) were well differentiated, 32 (11%) were moderately differentiated and 7 (2%) were poorly differentiated. The percentage of pink areas within tumors varied between differentiation grades. The combined group of moderate and poorly differentiated tumors displayed more branching (28%, P<0.001) and serpentine (62%, P<0.005) blood vessels compared to well differentiated tumors (8% and 38%, respectively). Moderate and poorly differentiated tumors displayed larger numbers of vessel types (3.3) compared to well differentiated tumors (2.6, P < 0.01). Branching and serpentine vessels both increased in incidence with increasing tumor depth (p<0.05).Conclusion:Grades of tumor differentiation in SCC display varying dermatoscopic vascular features. The incidence of branching and serpentine vessels increases with increasing tumor depth and the shift towards poor differentiation.

Background:Basal cell carcinoma (BCC) can present with indolent or aggressive subtypes. These subtypes usually display vascular features, which are often readily identified using dermatoscopy.Objective:Dermatoscopy vascular features of aggressive BCC were compared to superficial, superficial and nodular, and nodular BCC for diagnostic discrimination.Method:Dermatoscopy vascular features were recorded live direct from the patient for 1,098 consecutive BCC. Cases with potential confounding influences were excluded. These tumor vascular features included branching (arborizing), serpentine, dot, coil (glomerular), loop (hairpin) and linear vessels. The proportion of pink within the tumor, central versus peripheral tumor vessel distribution and the presence of large vessels within the tumor boundary were also recorded.Results:Different subtypes of BCC have distinctive vascular features. Aggressive BCC (n=213) displays a tumor area with no pink (12.2%) or less than half the area pink (27.2%) and absent vessels in the central tumor area (22.1%, CI 17.0%–28.1%, P<0.001) compared to other subtypes. Superficial BCC (n=284) have more than half the tumor area pink (84.9%) and absent large vessels (92.6%), CI 89.0%—95.1%. Nodular BCC (n=230) is characterized by larger vessels (45.7%, CI 39.3%–52.1%, P<0.001) as compared to other subtypes, as well as less dot, coil and loop vessels. Kappa values for all recorded features ranged from 0.48 to 1.0.Limitations:Aggressive BCCs within the combined aggressive group were not assessed separately.Conclusions:Diagnostic discrimination between different subtypes of BCC is facilitated by vascular feature assessment. Compared to other subtypes, aggressive BCC displays less or no pink and less or absent central tumor vessels.

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.