The value of high-frequency ultrasonography in the differential diagnosis of early mycosis fungoides and inflammatory skin diseases: A case-control study.

BACKGROUND The clinical manifestations of early mycosis fungoides (eMF) are non-specific and similar to inflammatory skin diseases. High-frequency ultrasonography (HF-US) can show small structure of skin lesions and is helpful to provide information objectively. MATERIALS AND METHODS A case-control study was designed in 62 patients with multiple erythemas and scales, including 18 eMF and 44 age-matched patients with eczema (EC) or psoriasis vulgaris (PsV). The most significant lesions were collected by 50 MHz HF-US. The assessment of ultrasound included epidermal morphology and thickness, infiltration depth, subepidermal low echogenic band (SLEB) boundary and thickness, internal echo, and number of linear acoustic shadows (LAS) behind the epidermis. The ultrasonic characteristics of eMF, EC, and PsV lesions were analyzed. RESULTS Epidermal thickness (P < .001, sensitivity 88.9%, specificity 75.0%) and SLEB thickness (P = 0.006, sensitivity 55.6%, specificity 90.9%) were useful for differential diagnosis of eMF and PsV/EC. When eMF was diagnosed by epidermal thickness < 0.2375 mm, the AUC was 0.845, which had the highest diagnostic efficacy among all ultrasound signs. In addition, compared with eMF and EC, the LAS number of PsV lesions was the highest and statistically significant. CONCLUSION The results showed that HF-US could provide some extra information in identification of eMF, EC, and PsV and has potential clinical value.