Determination of cell adhesion molecule expression and its diagnostic value in patients with mycosis fungoides

BACKGROUND: At the early stages of the disease, mycosis fungoides (MF) often exhibits clinical and morphological similarities with various benign dermatoses, which causes significant diagnostic difficulties. Despite the existing diagnostic algorithms for MF, challenges in timely diagnosis persist. This underscores the relevance of searching for new diagnostic markers, as well as expanding and refining the current panels for the immunohistochemical diagnosis of T-cell lymphoproliferative disorders. Our attention has been drawn to what we consider the most promising marker, CADM1.

AIM: The study examined the expression of the cell adhesion molecule 1 (CADM1) in skin tumor cells of patients with mycosis fungoides and in a comparison group of patients with plaque parapsoriasis (PP).

METHODS: This study included 65 patients aged 18 to 86 years. Of these, 35 patients were diagnosed with mycosis fungoides, and 30 patients with small plaque parapsoriasis formed the comparison group. All patients underwent histological examination, immunohistochemical analysis, and molecular genetic testing for T-cell clonality to confirm the diagnosis. Immunohistochemical staining for CADM1 (Cloud-Clone Corp.) was performed on paraffin-embedded tissue sections according to the protocol recommended by the manufacturer.

RESULTS: A comparative analysis of CADM1 expression levels was conducted between a group of patients with lymphoma (n=35) and a comparison group with parapsoriasis (n=30). The level of CADM1 expression was found to range from 10% to 90%. The mean expression value in the MF group was 59.4%, with an expression level of 70% being the most frequently observed.

To compare the mean CADM1 expression values between the groups, Welch's t-test was applied, which accounts for unequal variances and sample sizes. The analysis revealed a statistically significant difference between the lymphoma patient group (M = 59.43%, SD = 21.84) and the parapsoriasis group (M = 6.67%, SD = 8.02), t (44) = 13.28, p < 0.0001.

CONCLUSION: Our results revealed high CADM1 expression in mycosis fungoides patients. These findings suggest that CADM1 could be a valuable diagnostic marker for differentiating MF from parapsoriasis.