Necrotizing sialometaplasia masquerading as residual cancer of the lip

Necrotizing sialometaplasia is a benign disorder that histologically can mimic carcinoma. It is thought to develop as a result of ischemia or adjacent tissue injury. A patient is described who underwent a Mohs' micrographical fresh-tissue excision of one-third of the upper lip for basal cell carcinoma. By the time she was ready for reconstruction, a marked eczematous reaction developed to a polymyxin neomycin preparation (Neosporin ointment) at the wound edges. Reexcision of the wound margins before a flap reconstruction revealed necrotizing sialometaplasia on histopathological examination. This incidental finding fortunately was not mistaken for residual tumor. To prevent over-diagnosis and over-treatment of presumed malignancies, an awareness of necrotizing sialometaplasia is essential for all surgeons operating on mucosal surfaces in the head and neck.