title: Development of squamous cell carcinoma into basal cell carcinoma under treatment with Vismodegib.
abstract: BACKGROUND
  Basal cell carcinoma (BCC) is the most common cancer in humans. Vismodegib, a Hedgehog pathway inhibitor, has proved its effectiveness in treating non-resectable advanced BCC.
  
  
  OBJECTIVE
  However, its action on squamous cell carcinoma (SCC) is unknown. We present three SCC cases developed into BCC in vismodegib-treated patients.
  
  
  METHODS
  We have described three cases of patients developing SCC during treatment by vismodegib for BCC.
  
  
  RESULTS
  Patient 1 was treated with vismodegib for five facial BCC. Due to the progression of one of the lesions at month 3 (M3), a biopsy was performed and showed SCC. Patient 2 was treated with vismodegib for a large facial BCC. A biopsy was performed at M2 on a BCC area not responding to treatment and showed SCC. Patient 3 was treated with vismodegib for a BCC on the nose. Due to vismodegib ineffectiveness, a biopsy was performed and showed SCC.
  
  
  CONCLUSIONS
  Two similar cases have been described in the literature. This could be due to the appearance of the squamous contingent of a metatypical BCC or to the squamous differentiation of stem cells through inhibition of the hedgehog pathway.
  
  
  CONCLUSIONS
  In practice, any dissociated response of a BCC to vismodegib should be biopsied.
authors: Skin Cancer Unit, CHU Hôtel Dieu, Nantes, France.
authors: C
authors: C
authors: Saintes
authors: M
authors: M
authors: Saint-Jean
authors: A
authors: A
authors: Brocard
authors: L
authors: L
authors: Peuvrel
authors: J J
authors: JJ
authors: Renaut
authors: A
authors: A
authors: Khammari
authors: G
authors: G
authors: Quéreux
authors: B
authors: B
authors: Dréno
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000813:Anilides / Q000009:adverse effects*; D000970:Antineoplastic Agents / Q000009:adverse effects*; D002280:Basal Cell Carcinoma / Q000188:drug therapy* / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000139:chemically induced* / Q000473:pathology; D005153:Facial Neoplasms / Q000188:drug therapy* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016609:Neoplasms, Second Primary / Q000139:chemically induced* / Q000473:pathology; D011725:Pyridines / Q000009:adverse effects*; D012878:Skin Neoplasms / Q000188:drug therapy* / Q000473:pathology
chemical_list: D000813:Anilides; D000970:Antineoplastic Agents; C538724:HhAntag691; D011725:Pyridines