Follicular Induction and CK20+ Merkel Cells Overlying Cutaneous Focal Mucinosis
January 2019
in “
Journal of cutaneous pathology
”
TLDR Some skin growths with mucin can form hair follicles and resemble skin cancer, but a special stain can help tell them apart.
In a retrospective histological review of cutaneous focal mucinosis (CFM) lesions confirmed by skin biopsy from 2010 to 2015, it was found that 11% (11 out of 98) exhibited follicular induction, a phenomenon where the epidermis forms hair follicles due to an underlying process. This is a rare occurrence in CFM. Additionally, Cytokeratin 20 (CK20) immunostaining was performed on these 11 biopsies, revealing an increased density of CK20+ Merkel cells within the basaloid epidermal proliferations. The study concluded that CFM with follicular induction can closely resemble superficial basal cell carcinomas (BCC) histologically, especially in superficial shave biopsies, due to the mucinous stroma around the basaloid islands. Therefore, dermatopathologists should be aware of this similarity, and CK20+ staining may aid in differentiating CFM with follicular induction from BCC.
