Reduced Expression of RECK Protein May Help Differentiate Cutaneous Malignant Melanoma from Melanocytic Nevus

Abstract

Background: Differentiating between vertical growth cutaneous malignant melanoma (CMM) and predominantly intradermal benign melanocytic nevus (BMN) can be extremely challenging. Reversion-inducing cysteine-rich protein with Kazal motifs (RECK) is an endogenous inhibitor of many proteins that promote tumor invasion and progression. We investigated the difference in expression of RECK between CMM and BMN to determine whether RECK could assist in their differentiation.

Materials and methods: The expression of RECK in skin biopsies of 39 cases, including 20 cases of CMM and 19 cases of BMN, was evaluated by immunohistochemistry.

Results: Two out of 20 cases (10%) of CMM were positive for RECK, and all (100%) 19 cases of BMN exhibited positivity at different levels. In 7/8 cases of CMM adjacent to benign nevus cells, malignant melanoma cells did not express RECK, but benign nevus cells stained positively.

Conclusion: These findings suggest that immunohistochemical staining for RECK could be useful in the differential diagnosis between CMM and BMN.

Keywords: Melanoma; RECK; immunohistochemical stain; nevus; reversion-inducing cysteine-rich protein with Kazal motifs.