In recent years, the number of cases of cutaneous cancer has continued to grow. Annually, there are 2–3 million diagnoses of nonmelanoma cutaneous cancer and more than 130 thousand diagnosis of cutaneous malignant melanoma (CMM) globally [
9]. CMM is a cutaneous tumor caused by abnormal hyperplasia of melanoma. It features a high degree of malignancy, high rates of metastasis and recurrence, poor prognosis, and high mortality. Currently, typical CMM is diagnosed using the ABCDE standard [
10] and abnormality is classified according to the latest TNM staging standard [
11] issued by the American Joint Committee on Cancer (AJCC). Through diagnosis and staging, doctors can identify the extent of the surgery needed to remove the primary CMM lesion. However, due to the cytological morphology of CMM, the diversity of its histopathology, atypical tumors, and tumors without melanin, missed diagnosis and misdiagnoses are likely [
12]. Some research suggests that TPI can be used to distinguish abnormal from normal tissues, for example, Woodward et al. [
13] differentiated basal cell carcinoma (BCC), inflammatory tissues from normal tissues by analyzing the contrast in the image. Wallace et al. [
14] interpreted the difference in contrast as the difference in water content in specific tissues, which causes differences in their refractive index and absorption coefficients. Arbab et al. [
6] performed a TPI experiment on rat skin. The results showed that the reflection rate of burned tissue is higher than that of normal tissues between 0.5 and 0.7 THz. Sim et al. [
15] imaged the oral melanoma using TPI within the temperature range of −20°C–20°C. They found melanoma could be identified clearly in the image and the contrast of the image increased as temperature decreased. Fan et al. [
16] performed a TPI experiment on the trauma tissue of the human arm. The results showed that TPI can be used to distinguish scars from normal skin. So TPI has potential applications in the detection of CMM.