Mohs' micrographic surgery is a very reasonable technique for recurren
t carcinomas, avoiding unnecessary resection of healthy tissue. The ob
jective of the present work was to study the histological features of
sialometaplasia in Mohs' micrographic surgery. A 57-year-old male pati
ent presenting with a recurrent basal cell carcinoma successfully trea
ted with Mohs' micrographic surgery in 4 sessions and 10 stages is des
cribed. The last stages revealed histopathological features of sialome
taplasia. In conclusion, an accurate knowledge of the histopathologica
l features is important in order to differentiate sialometaplasia from
carcinoma and to avoid unnecessary resection of healthy tissue.