Pilomatrixoma causing irreversible peripheral eyebrow shedding: A case report

Pilomatrixomas are benign tumors derived from hair stromal cells; however, their exact etiology is unknown. A 31-year-old woman presented with a subcutaneous mass located precisely above the left eyebrow, with shedding of eyebrow hair around the mass, and the shedding area gradually expanded. Surgical removal of the mass failed to prevent eyebrow loss, and the entire left eyebrow shed 6 months postoperatively. Pathology and histology of the biopsy specimen revealed a pilomatrixoma comprising basaloid cells and ghost cells, with basaloid cells expressing high bcl-2 levels. Instead of apoptosis, the emergence and growth of pilomatrixoma-induced microinflammation around the hair follicles of the eyebrow may lead to eyebrow loss.