High-Frequency Ultrasound Quantification of Endophytic Growth Pattern: A Potential Imaging Indicator for Grading...

Cutaneous squamous cell carcinoma (cSCC) is the second most common type of skin cancer. While most tumors have a positive prognosis, poorly differentiated tumors increase the risk of negative outcomes. Few studies are available on noninvasive methods to determine the level of differentiation of cSCC before surgery. The objective of this study was to determine the degree of differentiation of cSCC using high-frequency ultrasound (HFUS).

This study included 117 lesions from 117 patients, of which 68 were well-differentiated, 30 were moderately differentiated, and 19 were poorly differentiated cSCC. We analyzed the clinical, appearance, histopathological, and HFUS characteristics of cSCC. The thickness characteristics measured by HFUS included the overall thickness of the tumor, the thickness of the tumor's endophytic part, and the proportion of endophytic thickness to the overall thickness.

The three groups did not show significant differences in their clinical and appearance features (all p > 0.017). However, on HFUS, the lesion total thickness, endophytic proportion, and surface keratinization were the significant features for identifying poorly differentiated cSCC. While a single indicator is not as effective as the combination of all three (all p > 0.05), the diagnostic accuracy of any two or all three indicators together did not show significant differences (p < 0.05).

HFUS can reveal internal morphological details of cSCC lesions, identifying poorly differentiated cSCC by analyzing total lesion thickness, endophytic proportion, and surface hyperkeratinization. Any two of these features can be as effective as using all three to diagnose poorly differentiated cSCC.