Fast-Growing Cutaneous Squamous Cell Carcinoma in a Patient Treated with Vismodegib

BACKGROUND: Vismodegib therapy achieves a breakthrough in patients with locally advanced basal cell carcinoma (BCC). Yet, long-term safety of hedgehog pathway inhibitors remains to be established, while drug resistance is becoming a new challenging issue. CASE REPORT: We report the case of a 90-year-old male initially referred for a locally advanced BCC of the nose. He had been previously treated by topical 5-fluorouracil for an adjacent microinvasive squamous cell carcinoma (SCC), with complete clinical response. Afterwards, vismodegib was initiated to treat his BCC. At week 16, both tumor and tumor ulceration obviously progressed. Palliative rhinectomy was performed. Histological examination found a deeply invasive SCC. CONCLUSION: Although our case must be interpreted with caution, a role of vismodegib as a promoter of cutaneous SCC should be considered, consistently with recently published evidence. Physicians should perform new biopsies whenever in doubt about new and/or progressive skin lesions in patients receiving hedgehog pathway inhibitors.